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Question: <p>I'm trying to look for a table for magnetic moments for all elements of the periodic table for my research project in computational chemistry, can anyone direct me to a suitable one?</p>
Answer: <p>Unpaired electrons will give rise to a magnetic moment equal to the 'spin only' value <span class="math-cont... | https://chemistry.stackexchange.com/questions/112948/table-for-magnetic-moments-for-all-elements-in-periodic-table |
Question: <p>Can someone explain me how can I use the periodic table in order to find the specific heat capacities of some elements? (for example, of Aluminium )</p>
<p>The question I have encountered is as follows:</p>
<blockquote>
<p>Given the specific heat capacities of the following liquids, use the periodic table ... | https://chemistry.stackexchange.com/questions/1258/specific-heat-capacity-and-the-periodic-table |
Question: <p>Why do some people say that hydrogen should be above lithium in the periodic table and others argue it should be above fluorine?</p>
Answer: <p>This comes down to the fact that hydrogen has a $1s$ valence shell, capable of holding only two electrons.</p>
<p>In some sense, hydrogen is like the halogens, i... | https://chemistry.stackexchange.com/questions/4164/where-hydrogen-belongs-in-the-periodic-table |
Question: <p>In searching online, I've noticed there are a lot of different ways to group the elements of the periodic table.</p>
<p>Take mercury in the two tables linked below, for example:</p>
<ul>
<li><a href="http://i.telegraph.co.uk/multimedia/archive/02101/periodic_2101916b.jpg" rel="nofollow">http://i.telegrap... | https://chemistry.stackexchange.com/questions/33453/periodic-table-groups-which-grouping-is-right |
Question: <p>I am developing a website and later on an app with the periodic table. The reason I started was that I thought almost all the other periodic tables was awfully ugly.
I do not only want to make it a well-looking periodic table, but I want to make it easy and smart to use combined with the design. </p>
<p>... | https://chemistry.stackexchange.com/questions/85676/what-do-you-chemists-need-from-a-periodic-table |
Question: <p>In “periodic table”, the adjective is related to the noun <em>period</em>, and <a href="http://www.etymonline.com/index.php?term=periodic&allowed_in_frame=0" rel="noreferrer">comes from</a> Ancient Greek <em>περίοδος</em> through French <em>périodique</em>. In “periodic acid”, it is formed from the pre... | https://chemistry.stackexchange.com/questions/306/should-one-pronounce-periodic-the-same-in-periodic-acid-and-periodic-table |
Question: <p>I'm familiar with the periodic table / periodic system, but I wonder why it's called "periodic" since there seems not much periodic about (there seems to be little or no predictability of which elements are stable) and from physics I know Z-value of elements and that is not periodic either. So what is a "p... | https://chemistry.stackexchange.com/questions/4529/what-is-a-period-of-the-periodic-table |
Question: <p>My physics lecturer was introducing the idea of what a Theory of Everything was, and said something like this:</p>
<blockquote>
<p>Other sciences have their own theories of everything too, fundamental axioms from which everything else can be derived from. In mathematics, we have ZFC, and well, the entir... | https://chemistry.stackexchange.com/questions/61680/does-organic-chemistry-somehow-defy-the-periodic-table |
Question: <p>The periodic table has 7 periods and they have 2,8,8,18,18... elements respectively from 1 to 7. But from what I understand, the periods each state the number of electron shells that the elements in that period has. So if that is the case, shouldn't period 3 have more elements, since it can hold up to 18 e... | https://chemistry.stackexchange.com/questions/34549/confusion-with-the-periodic-table |
Question: <p>On the periodic table, period 2 and 3, 4 and 5, 6 and 7 and so on have similar blocks, identical length and groups. What are such pairs of analogous periods called?</p>
Answer: <p>In a bit of a web search, there does not seem to be any particular names for families of periods in the Periodic Table. Howev... | https://chemistry.stackexchange.com/questions/7022/pair-of-analogous-periods-on-the-periodic-table |
Question: <p>Why there are three separate columns for 8B group in old version of the periodic table?</p>
Answer: | https://chemistry.stackexchange.com/questions/152244/my-question-is-regarding-periodic-table-why-there-are-three-columns-for-8b-grou |
Question: <p>What is the most rare element in periodic table? I have a lot of confusion about this.</p>
Answer: <p>Well, the first question to answer would be: where? The rarest element in the universe? the sun? in meteorites? on earth? in the ocean? in humans? We can tap in to the curated datasets provided by Mathe... | https://chemistry.stackexchange.com/questions/7462/what-is-the-most-rare-element-in-periodic-table |
Question: <p>We know that atomic radius decreases along a period and increases along a group. (Same goes for metallic character)</p>
<p>But if we take 2 elements A & B(A is at somewhere in the top and left in periodic table and B is somewhere is below and right of B) then which among A and B will have greater atomi... | https://chemistry.stackexchange.com/questions/163493/confusion-regarding-trends-in-modern-periodic-table |
Question: <p>I came across the following question:</p>
<blockquote>
<p>If each orbital can hold a max. of 3 e– what is the number of elements in the 4th period of the periodic table? </p>
</blockquote>
<p>I was unable to even start the thought process of answering the question because I'm rather horrible at discer... | https://chemistry.stackexchange.com/questions/57572/electronic-configuration-and-the-periodic-table |
Question: <p>My teacher said that on the periodic table there is a "nose" formed by Al, Zn, Ag, and Cd. She said that they are all fixed charged (+3, +2, +1, and +2 respectively), and said that if I write them in ionic equations, I just say Silver Nitrate instead of Silver (I) Nitrate. She also said to put all Al as +3... | https://chemistry.stackexchange.com/questions/123729/the-nose-of-the-periodic-table |
Question: <p>Reading about heavy water, I have found that the chemical formula for it can be written 2H<sub>2</sub>O or D<sub>2</sub>O.</p>
<blockquote>
<p>Deuterium is an isotope of hydrogen that is found in large quantities in water, more than one atom per ten thousand hydrogen atoms has a deuterium nucleus. The i... | https://chemistry.stackexchange.com/questions/112352/chemical-formulae-and-the-periodic-table-of-elements |
Question: <p>I was wondering why the elements in the periodic table were disposed the way they are. I understand, of course, that they are put in increasing atomic number fashion, but I'd like to know more about the topic. Could you link some reference that examine in detail the structure of the periodic table?</p>
An... | https://chemistry.stackexchange.com/questions/15926/according-to-what-criteria-was-the-periodic-table-of-elements-ordered |
Question: <p>Which is the most reactive element in the periodic table? Is it francium, caesium, lithium or fluorine?</p>
Answer: <p>Fluorine is the most reactive non radioactive element on periodic table.</p>
<p>It exists in gaseous form at room temperature and even reacts with glass. So it is almost impossible to st... | https://chemistry.stackexchange.com/questions/53831/which-is-the-most-reactive-element-in-the-periodic-table |
Question: <p>I wish to know the trends in the periodic table and why that trend exists, for the following parameters:</p>
<ol>
<li>Atomic size</li>
<li>Ionization energy</li>
<li>Metallic character</li>
<li>Positive ion size</li>
<li>Negative ion size</li>
<li>Electronegativity</li>
</ol>
<hr>
<p>My progress (if my ... | https://chemistry.stackexchange.com/questions/2843/what-trends-exist-in-the-periodic-table |
Question: <p>I have often wondered about diagonal relationships between elements on the periodic table, and the most often cited explanations revolve around charge-density considerations.</p>
<p>But other than that, what other factors could possibly contribute to this phenomenon?</p>
<p><strong>EDIT:</strong> What I ... | https://chemistry.stackexchange.com/questions/32591/diagonal-relationships-in-the-periodic-table |
Question: <p>Hydrogen is not in the first group as it was before and it is now placed above the periodic table? So why is it still categorized as a metal in some books?</p>
Answer: <p>There is a lot that could be said about this question, but a simple explanation goes like this:</p>
<ul>
<li><p>Some periodic tables c... | https://chemistry.stackexchange.com/questions/55464/what-is-the-position-of-hydrogen-in-the-periodic-table |
Question: <p>I am studying Periodic Table and have doubts in the group 3 (III-B) periods 6 and 7.</p>
<ol>
<li>If f-block is not a part of d-block, then why so they place inner transition metals in the boxes of group 3 periods 6, 7?</li>
<li>Since they place so, why are sometimes La and Ac placed while sometimes Lu and... | https://chemistry.stackexchange.com/questions/185425/periodic-table-group-3-period-6-7 |
Question: <p>Normally with the periodic table the lanthanide series is separated out because it's long and would make the table wide. I looked for an expanded version and found this:</p>
<p><a href="https://i.sstatic.net/VH9ax.png" rel="nofollow noreferrer"><img src="https://i.sstatic.net/VH9ax.png" alt="enter image d... | https://chemistry.stackexchange.com/questions/99223/what-is-the-true-depiction-of-the-periodic-table |
Question: <p>What are the different diagrams/tables used to organize the elements other than the Periodic Table? What are the advantages/disadvantages of each?</p>
Answer: <p>One periodic table that apparently physicists find useful is ADOMAH periodic table, for its usefulness is finding electron configuration of a pa... | https://chemistry.stackexchange.com/questions/901/what-are-the-alternatives-to-the-periodic-table-of-the-elements |
Question: <p>I was studying about the periodic table recently, and was reading a topic associated with oxides of halogens, and came across the following line</p>
<blockquote>
<p>The bromine oxides, $\ce{Br2O}$, $\ce{BrO2}$, $\ce{BrO3}$ are the least stable halogen oxides (<strong>Middle row anomaly</strong>) and exi... | https://chemistry.stackexchange.com/questions/31113/middle-row-anomaly-of-the-periodic-table |
Question: <p>How can one read from the periodic table the number of outer shell electrons that an atom has, to predict how these atoms will make bonds with other atoms? For example to see that hydrogen ($\ce{H}$) has 1 electron free, while carbon ($\ce{C}$) has 4 and oxygen ($\ce{O}$) has 2? This allows us to infer tha... | https://chemistry.stackexchange.com/questions/31615/reading-number-of-outer-shell-electrons-and-other-properties-from-periodic-table |
Question: <p>there are 118 currently existing elements on the periodic table, and recently I've found like 77 elements that quote on quote "may exist" on our periodic table. Is this true?</p>
Answer: | https://chemistry.stackexchange.com/questions/89409/is-there-any-evidence-that-there-are-75-extra-elements-on-the-periodic-table |
Question: <p>I am searching about some basics in chemistry. I was looking for the molecular structure of all periodic table element molecules.
eg: Hydrogen molecule: as <span class="math-container">$\ce{H2}$</span>; structure:<img src="https://i.sstatic.net/lwUhA.jpg" alt="enter image description here" /></p>
<p>I was ... | https://chemistry.stackexchange.com/questions/22228/molecular-structure-of-all-periodic-table-element-molecules-exceptional-cases-et |
Question: <p>According to the binding energy per nucleon vs mass number graph, it is observed that iron-56 has the maximum value of binding energy per nucleon ($\pu{8.75 MeV}$). It means that iron-56 is the most efficiently bound nucleus meaning that it has the least average mass per nucleon. This is the approximate b... | https://chemistry.stackexchange.com/questions/40407/is-iron-the-most-stable-element-in-the-periodic-table |
Question: <p>Why is there a diagonal line cutting through some of the nonmetals and metalloids on the periodic table in groups IIIA, IVA, VA, VIA, and VIIA?</p>
<p><img src="https://i.sstatic.net/3zpgH.jpg" alt="Periodic table of elements"></p>
<p>Is there any historical background about it?</p>
Answer: <p><strong>T... | https://chemistry.stackexchange.com/questions/6116/diagonal-line-going-through-groups-iiia-via-on-the-periodic-table |
Question: <p>I am looking for a full set of data on every element on the periodic table. (and if possible those only speculated about)</p>
<p>When I say full I mean everything. Electron configurations, Valence electrons, melting point, Atomic mass, Isotopes and what they decay into and all the rest.</p>
<p>Is there s... | https://chemistry.stackexchange.com/questions/7189/a-full-verion-of-the-periodic-table-for-computer-game |
Question: <p>Why exactly does hydride acidity increase across period and down group in periodic table? What is the explanation with respect to electrons? I can't figure this out because for 1st period etc H is an anion while for the right and middle of the periodic table H is a cation in compounds formed. I feel confus... | https://chemistry.stackexchange.com/questions/97667/why-does-hydride-acidity-increase-across-period-and-down-group-in-periodic-table |
Question: <p>Why are the groups of elements on the periodic table organized into areas represented by the letters s,p,d,f,g, and h?
What does this mean?</p>
Answer: <p>The letters are related to the electron orbitals, which were originally observed through spectroscopy. <a href="https://en.wikipedia.org/wiki/Electron_... | https://chemistry.stackexchange.com/questions/78557/on-the-periodic-table-why-are-groups-of-elements-organized-by-letter |
Question: <p>I'm currently reading in-depth about the layout of the Periodic Table, and I wondered why the table has 3 columns in its Group VIII:</p>
<p><a href="https://i.sstatic.net/ThqdHm.png" rel="noreferrer"><img src="https://i.sstatic.net/ThqdHm.png" alt="enter image description here"></a></p>
<p>As I understan... | https://chemistry.stackexchange.com/questions/50413/why-are-there-3-columns-in-group-viii-of-the-periodic-table |
Question: <p>In the standard Periodic Table layout , all the elements up to 56 are in order i.e are in the same layout table. However, lanthanides and actinides are always shown separately from the layout like in this layout:
<a href="https://i.sstatic.net/C4q1r.png" rel="noreferrer"><img src="https://i.sstatic.net/C4q... | https://chemistry.stackexchange.com/questions/10478/why-lanthanides-and-actinides-are-shown-separate-from-standard-periodic-table-la |
Question: <p>I am confused about the zig-zag pattern of metalloids in the periodic table. Why are metalloids arranged in a zig-zag line? Can anyone answer my question?</p>
Answer: <p>In addition to Pritt Balagopal's answer, in which he has clarified the trends in metallic character across the Periodic Table, I would a... | https://chemistry.stackexchange.com/questions/76568/why-are-metalloids-found-in-a-zig-zag-line-on-the-periodic-table |
Question: <p><a href="https://i.sstatic.net/Kysf7.jpg" rel="nofollow noreferrer"><img src="https://i.sstatic.net/Kysf7.jpg" alt="enter image description here"></a></p>
<p>Row 1: 2 elements</p>
<p>Row 2: 8 elements</p>
<p>Row 3: 8 elements</p>
<p>Row 4: 18 elements</p>
<p>Row 5: 18 elements</p>
<p>Row 6: 32 elemen... | https://chemistry.stackexchange.com/questions/44640/in-the-periodic-table-why-doesnt-the-2nd-row-have-exactly-2-elements |
Question: <p>Period 1 of the periodic table contains 2 elements (<span class="math-container">$1s^1$</span> and <span class="math-container">$1s^2$</span>).</p>
<p>Period 2 contains 8 elements (<span class="math-container">$2s^1$</span>, <span class="math-container">$2s^2$</span>, <span class="math-container">$2p^1$</... | https://chemistry.stackexchange.com/questions/119812/why-does-period-3-of-the-periodic-table-contain-8-elements-instead-of-18 |
Question: <p>I understand thermodynamics in a physicsy way - at the level of Callen's <em>Thermodynamics</em>. However, my chemical thermodynamics is quite rusty: concepts like fugacity and activity coefficients are only vaguely familiar from undergrad courses.</p>
<p>I'm looking for a <em>well written, rigorous and s... | https://chemistry.stackexchange.com/questions/34724/best-guide-to-chemical-thermodynamics |
Question: <p>I just started learning chemical thermodynamics and have come upon the definitions for extensive and intensive properties. I had a great deal of confusion over the exact meaning of intensive properties, but I believe I have come to a proper understanding of it after doing some extra reading. I will present... | https://chemistry.stackexchange.com/questions/39499/intensive-properties-clarification-chemical-thermodynamics |
Question: <p>Can one be understood on the basis of the other or are they not interrelated at all?</p>
<p>The first thing my kinetics textbook demonstrated was how thermodynamics ignores time taken for a process whereas kinetics considers the time and rate of the process and hence kinetics is a more effective way to vi... | https://chemistry.stackexchange.com/questions/44155/what-is-the-relation-between-chemical-thermodynamics-and-chemical-kinetics |
Question: <blockquote>
<p>For a reaction taking place in a container in equilibrium with its surroundings, the effect of temperature on its equilibrium constant <span class="math-container">$K$</span> in terms of change in entropy is described by:</p>
<p>(A) With the increase in temperature, the value of <span class="m... | https://chemistry.stackexchange.com/questions/132737/entropy-and-equilibrium-constant-chemical-thermodynamics |
Question: <p>We know that in thermodynamics, reversible process never occur since entropy should be conserved. However, in chemistry we do have a lot of reversed chemical reactions that forms reactants from products, previously formed by a direct reaction. So, what is the misunderstanding here?</p>
Answer: <p>There is... | https://chemistry.stackexchange.com/questions/108623/whats-the-difference-between-reversible-process-in-thermodynamics-and-reversible |
Question: <p>I took organic chemistry a few years ago at my university, and although I went through the motions to pass the exams, I didn't understand the thermodynamic reasoning behind <em>why</em> the reactions actually occurred. For instance, I memorized that Claisen Condensation reactions occur between two esters i... | https://chemistry.stackexchange.com/questions/115221/thermodynamics-behind-organic-chemical-reactions |
Question: <blockquote>
<p>Which of the following is/are correct for spontaneous isothermal
chemical reaction?</p>
<p>(A) <span class="math-container">$\Delta H = 0$</span>, because <span class="math-container">$\Delta T = 0$</span></p>
<p>(B) <span class="math-container">$\Delta S = 0$</span></p>
<p... | https://chemistry.stackexchange.com/questions/106828/thermodynamics-of-a-spontaneous-isothermal-chemical-reaction |
Question: <blockquote>
<p>Chemical reactions occur at constant temperature and pressure.</p>
</blockquote>
<p>Consider a gaseous, equilibrium reaction: <span class="math-container">$\ce{2NO2(g) <=> N2O4(g)}$</span>. Most questions/textbooks formulate such questions by stating: <em>The reaction happens at (<span c... | https://chemistry.stackexchange.com/questions/138417/thermodynamics-of-chemical-reactions-at-constant-pressure |
Question: <p>In chemical thermodynamics, the condition "constant temperature and pressure" appears almost everywhere. However, I felt a small ambiguity in the phrase so I wanted to clear my doubts. When we say "constant <span class="math-container">$T$</span> and <span class="math-container">$p$</span>&q... | https://chemistry.stackexchange.com/questions/141929/meaning-of-constant-t-and-p |
Question: <p>Wikipedia article on a <a href="https://en.wikipedia.org/wiki/Component_(thermodynamics)" rel="nofollow">component (in thermodynamics)</a> first mentions that:</p>
<blockquote>
<p>In thermodynamics, a <strong>component</strong> is a chemically-independent constituent
of a system. The number of compone... | https://chemistry.stackexchange.com/questions/38896/on-the-notion-of-a-component-in-thermodynamics |
Question: <p>I have a book at home called <a href="https://www.wiley.com/en-us/Chemical+Thermodynamics+for+Process+Simulation,+2nd,+Completely+Revised+and+Enlarged+Edition-p-9783527343256" rel="nofollow noreferrer">Chemical Thermodynamics for Process Simulation</a> (I have the first edition) and at the very beginning o... | https://chemistry.stackexchange.com/questions/122344/is-it-really-possible-for-a-liquid-to-stay-afloat-a-gas-vapor |
Question: <p>The way kinetics is taught at the undergraduate level (Arrhenius and collision theory) chemical equilibrium is determined governed immensely by activation energy of the reaction. According to thermodynamics, however equilibrium is a function of free energy change. In a way, thermodynamics and kinetics seem... | https://chemistry.stackexchange.com/questions/25077/kinetics-vs-thermodynamics |
Question: <p>I'm a high school student with basic knowledge about chemical thermodynamics. I have three questions regarding the thermodynamic state functions $H, S, G$. I have searched a lot in textbooks but they don't give the complete information as to whether the properties taken are that of the system or surroundin... | https://chemistry.stackexchange.com/questions/82322/chemical-thermodynamic-functions |
Question: <p>I'm not a chemist, but I need some insight into chemical thermodynamics. </p>
<p>In the book that I'm reading <a href="http://www.amazon.co.uk/Physical-Chemical-Equilibrium-Engineers/dp/0470927100/ref=sr_1_1?ie=UTF8&qid=1374225908&sr=8-1&keywords=physical%20and%20chemical%20equilibrium%20for%2... | https://chemistry.stackexchange.com/questions/5625/why-are-partial-molar-gibbs-energy-and-gibbs-energy-per-mol-equal |
Question: <p>In the book of Chemical, biochemical and engineering thermodynamics 4th edition from Stanley I. Sandler (Wiley, 2006), there is a problem about the ammonia producing reaction at page 770.</p>
<p>13.17 The simple statement of the LeChatelier-Braun principle
given in Sec. 13.1 leads one to expect that if
th... | https://chemistry.stackexchange.com/questions/53324/chemical-equilibrium-and-le-chatelier-braun-for-ammonia-production |
Question: <p>Is Light/Radiant Energy considered Kinetic Energy or Potential Energy?</p>
<p>I have started studying Thermodynamics, and the concept of internal energy was introduced, and defined as the sum of kinetic and potential energies of a system.</p>
<p>Another important definition was that:</p>
<p>ΔU = q + w , wh... | https://chemistry.stackexchange.com/questions/180479/is-light-energy-defined-as-work-in-thermodynamics |
Question: <p>Thermodynamics has always been a tough thing for me. There are lots of assumptions in this subject (those assumptions, I know, are necessary, I know the science of thermodynamics is a very practical science).<br>
First Law of Thermodynamics states mathematically:
<span class="math-container">$$\Delta U=Q+W... | https://chemistry.stackexchange.com/questions/119640/relation-between-first-law-of-thermodynamics-and-ideal-gas-law |
Question: <p>I'm using the following handbook <em>"Engineering and Chemical Thermodynamics 2nd edition"</em> by Koretsky. In the book they have an alternate formulation for <em>h(P,T)</em> though it was never explained how they got it (<a href="https://i.sstatic.net/R3HrJ.jpg" rel="nofollow noreferrer">source... | https://chemistry.stackexchange.com/questions/166677/alternate-formulation-of-hp-t |
Question: <p>There are 5 most common <a href="https://en.wikipedia.org/wiki/Thermodynamic_potential#:%7E:text=It%20is%20the%20energy%20of,from%20an%20expression%20for%20U." rel="nofollow noreferrer">thermodynamics potential</a> -</p>
<p><a href="https://i.sstatic.net/mfkxV.png" rel="nofollow noreferrer"><img src="https... | https://chemistry.stackexchange.com/questions/175333/thermodynamics-potential-and-differences-between-them |
Question: <p>In my thermodynamics course, we introduced the chemical potential as a modification of the first + second law of thermodynamics in the case of a system that can exchange particles with its surroundings (consider only PV work):</p>
<p><span class="math-container">\begin{equation}
dU = TdS - pdV + \sum_{j=1}... | https://chemistry.stackexchange.com/questions/160446/meaning-of-chemical-potential-in-chemical-reactions |
Question: <p>I wonder if there is a way to measure the chemical potential of a substance in a two-component mixture and also to account for its dependence on the number of moles. Explaining it further, suppose there is a mixture of a light component (like methane, C1) and a heavier one (like C20). Given temperature and... | https://chemistry.stackexchange.com/questions/75115/how-to-measure-chemical-potential |
Question: <blockquote>
<p><strong>This question has been re-asked on <a href="https://hsm.stackexchange.com/">History of Science and Mathematics</a>:</strong><br>
<a href="https://hsm.stackexchange.com/q/3581">Who is Hræðraford, the “learned clerk” “writing in modern chemical Latin”?</a></p>
</blockquote>
<hr>
<p... | https://chemistry.stackexchange.com/questions/14040/who-is-hr%c3%a6%c3%b0raford-the-learned-clerk-writing-in-modern-chemical-latin |
Question: <p>suppose a system in chemical equilibrium like ice melting to form water and said water freezing into ice again. it seems to me that a state in chemical equilibrium would have less entropy that a state that isn't in equilibrium since (at least intuitively), the number of microstates that yield a macrostate ... | https://chemistry.stackexchange.com/questions/186796/does-lechateliers-principle-contradict-the-second-law-of-thermodynamics |
Question: <p>I just started reading <em>Thermodynamics</em> by Enrico Fermi; he started defining <em>state of a system</em> for <em>homogeneous mixture of several chemical compounds</em> & then <em>non-homogeneous system</em> as: </p>
<p><img src="https://lh3.googleusercontent.com/-h94NSuXpbfc/VfwufkLkYfI/AAAAAAAA... | https://chemistry.stackexchange.com/questions/37544/difference-between-homogeneous-mixture-of-several-chemical-compounds-non-ho |
Question: <p>In the book, it is mentioned the formula for <span class="math-container">$\Delta U$</span> in a bomb calorimeter without any derivation:</p>
<blockquote>
<p><span class="math-container">$$\Delta U = q_v = \frac{Q\times M\times \Delta T}{m}$$</span>
where
<span class="math-container">$$Q=\textrm{heat capac... | https://chemistry.stackexchange.com/questions/144442/confusion-in-calculating-delta-u-from-a-bomb-calorimeter |
Question: <p>I know about the <a href="https://en.wikipedia.org/wiki/Belousov%E2%80%93Zhabotinsky_reaction" rel="nofollow noreferrer">Belousov-Zhabotinskii reaction</a> as an example of "chemical oscillator", e.g. a reaction that can produce repeating patterns over time as it exhausts its reagents. I also know about th... | https://chemistry.stackexchange.com/questions/70586/reference-request-review-paper-overview-of-chemical-oscillators |
Question: <p>This is not a homework question. I am not in any course of study. The following question arises from my personal curiosity. If 1 mole of sodium sulfate and 2 moles of potassium chloride are dissolved in water, and the solution is gradually evaporated, which salts precipitate, and in which order?</p>
<p>Th... | https://chemistry.stackexchange.com/questions/134484/which-salts-precipitate-from-a-potassium-sodium-chloride-sulfate-solution |
Question: <p>I'm studying equilibria and thermodynamics and came across these two terms.</p>
<p>My problem is, unlike other thermodynamic properties that I can understand physically like volume, pressure, enthalpy etc. <em>do these two quantities have physical significance</em> or, is it just that we define fugacity (w... | https://chemistry.stackexchange.com/questions/145224/physical-significance-of-chemical-potential-and-fugacity |
Question: <p>I am studying solutions for my thermodynamics course and I am a little confused about the chemical potential of a solute. I found the following from Atkins:</p>
<blockquote>
<p>For a solute $\ce B$,obeying Henry's Law $p_\ce B=K_\ce B\, x_\ce B$, where $x_\ce B$ is the molar fraction</p>
</blockquote>
... | https://chemistry.stackexchange.com/questions/49197/what-is-the-difference-between-standard-chemical-potential-%ce%bc-standard-and-the |
Question: <p>I'm taking chemical thermodynamics this semester, and currently seeing things like the Maxwell's Relations.</p>
<p>My professor never uses explicitly the variable "n" and always works with molar quantities like $\bar{V}$ and stuff like that.</p>
<p>I think this simplifies the algebra a great deal, and ca... | https://chemistry.stackexchange.com/questions/26785/will-all-thermodynamic-equations-have-a-linear-dependence-with-moles |
Question: <p>Can anyone help me to understand what the "Chemical Potential" is? I can see that in batteries the electrical energy is stored as "chemical potential", according to <a href="http://www.sciencedirect.com/science/article/pii/S1369702115003181" rel="nofollow noreferrer">this</a>:</p>
<bloc... | https://chemistry.stackexchange.com/questions/66863/understanding-chemical-potential-li-ion |
Question: <p>I want to ask a question about chemical potential, <span class="math-container">$\mu$</span>.</p>
<p>I dislike the use of integrals to describe quantities in thermodynamics. If we observe the definition of chemical potential for constant pressure:</p>
<p><span class="math-container">$$\mu_i = \left(\frac{\... | https://chemistry.stackexchange.com/questions/136948/integration-of-chemical-potential |
Question: <p>We're learning about chemical reactions in class and we recently did an experiment where we combined copper and nitric acid. Both were at relatively room temperature and when they were combined the temperature rose very quickly. Isn't this contradicting the first law of thermodynamics? If the thermal energ... | https://chemistry.stackexchange.com/questions/41664/where-does-the-thermal-energy-come-from-in-a-chemical-change-when-two-substances |
Question: <p>(This question is taken from Problem 1.1(b) of the book Chemical Thermodynamics: Principles and Applications.)<span class="math-container">$\require{begingroup} \begingroup \newcommand{\pd}[3]{\left(\frac{\partial #1}{\partial #2}\right)_{\!#3}}$</span></p>
<blockquote>
<p>Prove <span class="math-contai... | https://chemistry.stackexchange.com/questions/126955/proving-a-thermodynamic-relation-between-partial-h-partial-t-p-and-part |
Question: <p>The fundamental equation of thermodynamics, as us chemists (and chemical engineers!) are used to seeing it, is </p>
<p>$$ dG = - S~dT + V~dP + \sum_{i}\mu_i~dN_i$$</p>
<p>This gives the Gibbs free energy as a function of temperature, pressure, and composition, <em>assuming there are no other relevant for... | https://chemistry.stackexchange.com/questions/33329/fundamental-equation-of-thermodynamics-for-magnetocaloric-materials |
Question: <p>After doing some research and reading I found some problems which I will try to state as clearly as possible. </p>
<p>The definition of Gibbs Free Energy says "<em>the greatest amount of mechanical work which can be obtained from a given quantity of a certain substance in a given initial state, without i... | https://chemistry.stackexchange.com/questions/122162/what-is-the-true-meaning-of-gibbs-energy-and-chemical-potential |
Question: <p>Engel and Reid's <em>Physical Chemistry</em> [1, p. 308] defines the electrochemical potential in terms of the charge in units of the electron charge <span class="math-container">$(z),$</span> Faraday constant <span class="math-container">$(F),$</span> and electrical potential <span class="math-container">... | https://chemistry.stackexchange.com/questions/174677/why-is-electrochemical-potential-defined-as-sum-of-electrical-potential-and-appa |
Question: <p><span class="math-container">$ΔG=-nFe$</span> (<a href="https://chemistry.stackexchange.com/questions/72457/why-delta-g-nfe-and-not-f-integraldne/176835#176835">example</a>) and <span class="math-container">$μ = μ° + RT\ln a$</span> are used very frequently in chemical thermodynamics.</p>
<p>However, if th... | https://chemistry.stackexchange.com/questions/184433/how-to-derive-the-chemical-potential-of-an-ideal-solution-of-a-non-volatile-solu |
Question: <p>In thermodynamics, to find the expression for the chemical potential of a pure gas, we can find this expression:</p>
<p><span class="math-container">$$\frac{\mathrm d\mu}{\mathrm dP} = \frac{\mathrm dV}{\mathrm dn} = \frac{RT}{P} \quad \text{(from $\frac{\mathrm dg}{\mathrm dP} = V$)}.$$</span></p>
<p>But ... | https://chemistry.stackexchange.com/questions/188654/why-does-the-formula-for-chemical-potential-change |
Question: <p>I have a system of a pure ideal gas <span class="math-container">$a$</span>, which I call 'the reference', with a known <span class="math-container">$P^{ref}, V^{ref}, T^{ref}$</span> and <span class="math-container">$n^{ref}_a$</span>. I know the chemical potential formula for an ideal gas, so can calcula... | https://chemistry.stackexchange.com/questions/167457/can-chemical-potential-be-directly-measured-like-this |
Question: <p>I study physical chemistry on my own and I have to decide in which order I learn the following topics
These are my topics:</p>
<p>Statistical Thermodynamics (especially entropy, partition function, Boltzmann factor..)/
Maxwells Relations/
Thermodynamic Potentials/
Chemical potential/
Colligative propertie... | https://chemistry.stackexchange.com/questions/127738/in-which-order-should-i-learn-thermodynamic |
Question: <p>I haven’t quite reached the point where I can read a full-fledged text on chemical kinetics and thermodynamics yet, so bear with me, please. </p>
<p>I’m wondering why a value like $K_\text{eq} = \frac{[\ce{NO}]^2[\ce{O2}]}{[\ce{NO2}]^2}$ wouldn't have units of M?</p>
Answer: <p>I goofed up the first time... | https://chemistry.stackexchange.com/questions/1137/why-are-equilibrium-constants-unitless |
Question: <p>Another statement of second law of thermodynamics can be formulated in terms of system properties and not properties + surroundings (isolated system). For a closed system at constant temperature and pressure:</p>
<p><span class="math-container">$$dG_{T,p,n_i} \leq 0$$</span></p>
<p><strong>Are <span class=... | https://chemistry.stackexchange.com/questions/152616/do-the-differential-expressions-of-second-law-of-thermodynamics-imply-a-smooth-i |
Question: <p>One of the most fundamental equations in chemical thermodynamics states: <span class="math-container">$$ \Delta_rH_m^⦵ = \Delta_rG_m^⦵ + T\Delta_rS_m^⦵ $$</span>
If we look at this equation in context of net chemical reaction in electrolytic or galvanic cell, it is usually interpreted as follows: Enthalpy ... | https://chemistry.stackexchange.com/questions/151090/entropy-changes-in-electrolytic-galvanic-cell |
Question: <p>In the textbook Electrochemical Systems by Newman and Alyea, Chapter 14: The definition of some thermodynamic functions, chemical potential of component (ionic or neutral) is written as a function of absolute activity: <span class="math-container">$$\mu_i=RT\ln \lambda_i \tag{1}$$</span></p>
<p>where <span... | https://chemistry.stackexchange.com/questions/172573/concept-of-absolute-thermodynamic-activity |
Question: <p>This may be a stupid question but I would like to know what prevents chemical reactions from happening among common objects in everyday life? The opposite would be, what requirements must be met for chemical reactions?</p>
<p>For example, as I am typing this what prevents no reaction between my fingers an... | https://chemistry.stackexchange.com/questions/71387/what-prevents-everyday-objects-from-reacting |
Question: <p>In <em>Molecular Thermodynamics of fluid phase equilibria</em> by Prausnitz et al. [1] the authors recommend to use the following equation which gives the fugacity of component <span class="math-container">$i$</span> in terms of independent variables <span class="math-container">$V$</span> (volume) and <sp... | https://chemistry.stackexchange.com/questions/112989/proving-a-relation-for-fugacity-of-component-i-in-term-of-independent-variables |
Question: <p>From this question on Physics SE <a href="https://physics.stackexchange.com/questions/7284/">Thermodynamics of evaporation</a>:</p>
<blockquote>
<p>Now imagine the experiment is repeated but instead of vacuum conditions, the water is pressurized with nitrogen at 1 atm. According to the phase diagram of wat... | https://chemistry.stackexchange.com/questions/152504/will-addition-of-inert-gas-change-the-vapour-pressure-of-a-liquid |
Question: <p>Let $\sum_A \nu_A A \rightarrow \sum_B \nu_B B$ be a general reaction whose progress during time interval $dt$ is measured by $d\zeta$, so the amount of reactants consumed and products generated in mole would be $d N_i=\nu_i d\zeta$, wherein, $\nu_i$ would take negative values for the reactants being consu... | https://chemistry.stackexchange.com/questions/14012/how-can-we-justify-setting-the-affinity-sum-i-mu-i-nu-i-equal-to-zero-at-ch |
Question: <p>I <em>think</em> I've found a mistake in my thermodynamics textbook, <em>Chemical Thermodynamics for Process Simulation</em>, but as thermodynamics is hard and I'm a relative novice, I wanted to check here.</p>
<p>The textbook, in talking about partial molar Gibbs excess functions of species in solutions,... | https://chemistry.stackexchange.com/questions/36875/how-are-partial-molar-gibbs-excess-functions-correctly-defined |
Question: <p>I'm having difficulties understanding this problem.</p>
<p>We have in the problem that $K_\mathrm a$ for $\ce{HCN} = 6.2\cdot10^{-10}$ and $K_\mathrm b$ for $\ce{NH3} = 1.8\cdot10^{-5}$.</p>
<ol>
<li>Write chemical equations to represent the dissociation of $\ce{NH4CN}$ in water, and the acid-base equili... | https://chemistry.stackexchange.com/questions/14857/acid-base-equilibrium-of-nh4cn |
Question: <p>Suppose we had a closed system proceeding according to, </p>
<p>$$\ce A +2\ce B \rightleftharpoons 2 \ce C$$</p>
<p>And that three experiments produced the following concentration data. </p>
<p>Experiment 1:</p>
<p>\begin{array}{|c|c|} \hline
{\rm \small Species} & {\rm \small concentration} \\\hli... | https://chemistry.stackexchange.com/questions/51834/acid-base-equilibrium |
Question: <p>I'm having trouble finding anything meaningful in textbooks or searches. My question is what is the correct notation for writing acid-base reactions when their strengths are varying? I know that theoretically all reactions are reversible but when is it appropriate to use equilibrium arrows for certain acid... | https://chemistry.stackexchange.com/questions/165665/notation-for-acid-base-reactions-of-differing-strengths-equilibrium |
Question: <p>While reading an organic chemistry textbook I saw the following Formula for calculating equilibrium constant of an acid-base reaction</p>
<p>Consider following acid base reaction in which <span class="math-container">$\ce{HA}$</span>(reactant acid) and <span class="math-container">$\ce{HB+}$</span>(produc... | https://chemistry.stackexchange.com/questions/150940/equilibrium-constant-expression-for-an-acid-base-reaction |
Question: <p>I am trying to find the equilibrium value for different acid-base reactions. I have understood that when an acid and base are in an aqueous solution, many different reactions will occur. By combining these reactions, and multiplying their equilibrium constants, we can find the equilibrium value for an acid... | https://chemistry.stackexchange.com/questions/171444/calculating-equilibrium-constant-for-a-general-acid-base-reaction |
Question: <p>Should the equilibrium constant <span class="math-container">$K$</span> be calculated at the end of an acid-base titration or can we calculate it in the middle of the titration for example? If so, will the calculated equilibrium constant be equal to the equilibrium constant calculated from the final state ... | https://chemistry.stackexchange.com/questions/108602/can-equilibrium-be-calculated-at-any-time-of-an-acid-base-reaction-and-still-be |
Question: <p>Let's talk about the following compounds - water and methanol. </p>
<ol>
<li><p>We know that <em>methanol is slightly more acidic than water</em>, because water's ability to donate a proton as an acid is reduced due to extensive hydrogen bonding.
The $\mathrm{p}K_\mathrm{a}$ values are approximately $15.5... | https://chemistry.stackexchange.com/questions/94188/how-to-justify-this-contradiction-in-acid-base-equilibrium-of-methanol-and-water |
Question: <p>While deriving the relation between $K_a$ and $K_b$ in ionic equilibrium topic, say I take an example of</p>
<p>$$
\ce{NH4+ + H2O -> NH3 + H3O+} \tag{1}\label{1}
$$</p>
<p>The $K_a$ of this reaction is:</p>
<p>$$
\frac{\ce{[NH3][H3O+]}}{\ce{[NH4+][H2O]}}
$$</p>
<p>Now $\ce{NH3}$ is a conjugate base ... | https://chemistry.stackexchange.com/questions/65255/derivation-of-relation-between-acid-and-base-equilibrium-constants |
Question: <p>Suppose I want to make a buffer solution in any of the three ways possible with dihydrogen phosphate as my weak acid. In the first way, a certain ratio of the weak acid and its conjugate base are added at once to form the buffer. Why does this not return to the equilibrium described by its Ka value instead... | https://chemistry.stackexchange.com/questions/101085/why-dont-buffer-solutions-return-to-equilibrium |
Question: <p>My former question <a href="https://chemistry.stackexchange.com/questions/188136/is-deprotonation-limiting-the-product-formation-in-this-thiohydantoin-synthesis">Is deprotonation limiting the product formation in this thiohydantoin synthesis?</a>
made me wonder to what extent the KOH deprotonates the imide... | https://chemistry.stackexchange.com/questions/188241/can-we-estimate-acid-base-reaction-equilibrium-in-non-aqueous-media |
Question: <p>My question is in regards to acid base reaction that take place in larger chemical reaction in orgo. Like, I understand acid base reaction, how to qualitatively check which is stronger acid or base or where equilibrium lies, very well. But i feel that when I am trying to study the mechanism of series of ot... | https://chemistry.stackexchange.com/questions/71300/how-do-you-make-sense-of-acid-base-reactions-in-organic-chemistry |
Question: <p>From what I understand, the concentration of hydronium and hydroxide molecules is constant in pure water (and equals $10^{-7}\ \text{M}$, which is measured experimentally). </p>
<p>What I don't understand is why this remains true for an aqueous solution with an acid or base in it. Shouldn't it affect thes... | https://chemistry.stackexchange.com/questions/41696/acid-base-dissociation-constants-relationship |
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