difficulty int64 6 10 | source stringclasses 2
values | domain stringclasses 1
value | conversations listlengths 2 2 |
|---|---|---|---|
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "When white light that has passed through sodium vapor is viewed through a spectroscope, the observed spectrum has a dark line at 5890 Å. Explain this observation."
},
{
"from": "gpt",
"value": "<think> Okay, so the question is about why there's a dark line at 5890 Å ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Assertion: Chlorine gas disproportionates in hot and conc. NaOH solution.\\nReason: NaCl and NaOCl are formed in the above reaction."
},
{
"from": "gpt",
"value": "<think> Okay, so I need to figure out if the assertion and reason given here are correct, and if the re... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "The question is about the approximation techniques available in the path integral formulation and their equivalents in the context of the traditional Feynman-Dyson expansion (aka diagrammatic techniques). Of course, the Feynman-Dyson expansion can be also done in terms of path i... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Number of sigma bonds in P4O6 is: (a) 6 (b) 7 (c) 8 (d) 16 (AIEEE, 2002)"
},
{
"from": "gpt",
"value": "<think> Okay, so I need to find the number of sigma bonds in P4O6. Hmm, let me start by recalling what a sigma bond is. Sigma bonds are the primary bonds formed be... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Cholesterol is an essential component of the plasma membrane, but people who have very high levels of cholesterol in their blood (hypercholesterolemia) tend to have heart attacks. Blood cholesterol is carried in the form of cholesterol esters in low-density lipoprotein (LDL) par... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I want to build the following device, but I'd like to understand the physics behind it so that I can optimize the surface area and volume of the pipe. The device in its cross section looks as follows:\n\nBasically this is a copper spiral filled with frozen water which you can su... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "The problem states that a ball is dropped from rest and falls under the influence of gravity (neglecting air resistance). At the same time, another ball is thrown with an initial velocity of v0 from a point that is 10 meters horizontally away and 5 meters below the first ball (s... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Have been really struggling for some considerable time to understand the universal limitation of speed i.e. it is not possible to travel faster than the speed of light. In particular - what is the limiting factor? Is it something physical that can be understood (e.g. is there an... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "CH3CH2CH2CH2Br + KOH undergoes an E2 reaction since a secondary halide reacts with a strong base to yield an elimination product. The major product is (Z)-3-methyl-2-pentene, and a small amount of 3-methyl-1-pentene is also formed. What is the major product of the elimination re... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Strong oxidizing agents convert phenols to quinones. Reaction with Fremy's salt to form a quinone occurs by a radical mechanism. The redox reaction quinone → hydroquinone occurs readily. Ubiquinones are an important class of biochemical oxidizing agents that function as a quinon... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I've seen this claim made all over the Internet. It's on Wikipedia. It's in John Baez's FAQ on virtual particles, it's in many popular books. I've even seen it mentioned offhand in academic papers. So I assume there must be some truth to it. And yet, whenever I have looked a... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "The hepatic enzyme catalyzing the reaction: Fatty Acyl CoA + cholesterol → Cholesterol ester + CoA\\nA. LCAT \\nB. ACAT \\nC. Lysolecithinase \\nD. HMG CoA reductase \\nE. HMG CoA lyase"
},
{
"from": "gpt",
"value": "<think> Okay, so I have this question here abo... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Recently I have read a lot online about the EPR argument and Bell's inequalities and its implications. When comparing what people write there online with the actual research articles of Einstein and Bell, it seems to me - put drastically - that people online talk about something... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Write a balanced ionic equation for the reaction of \\( \\text{Cr}_2\\text{O}_7^{2-} \\) with \\( \\text{C}_2\\text{H}_3\\text{OCl} \\) in acid solution, given that \\( \\text{CO}_2 \\) and \\( \\text{Cl}_2 \\) are the two main products from the organic compound."
},
{
"... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "11. Give a chemical test to distinguish between the following pairs of compounds.\\n- (i) 2-Butyne and 1-Butyne\\n- (ii) Methanol and ethanol"
},
{
"from": "gpt",
"value": "<think> Okay, I need to figure out the chemical tests for distinguishing between pairs of comp... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Things are not going well. You've just had a brief but tense meeting with your research advisor that you will never forget, and it is clear that your future in his lab is in doubt. He is not fond of your habit of working late and sleeping late; he thinks it is at the root of you... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "In Chapter 13, we learned that the harmonic-oscillator model can be corrected to include anharmonicity. The energy of an anharmonic oscillator was given as (Equation 13.21)\\n\\n\\[\\n\\tilde{\\varepsilon}_v = \\left( v + \\frac{1}{2} \\right) \\tilde{\\nu} - \\tilde{x} \\tilde{... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "A and B are two non-volatile solids. A is dissolved in a solvent to give a dilute solution which is dissociated (degree of dissociation \\( \\alpha \\)). In the same solvent with the same molal concentration B is dimerised (degree of association \\( \\beta \\)). The elevation of... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I know that many closed form expressions exists for finding the final equilibrium temperature of a gas/liquid/solid mixture if the pressure is held constant, or if the solid/liquid does not change phase, but what about a simple case of a single solid being heated through a perfe... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I was thinking the other day of a system in which you eject mass. And then I wonder whether it was more efficient to throw a big mass or many little. Let me put it in other terms.\nSuppose you are moving at a constant speed $v_0$ in a car with a total mass $M$. Then you decide t... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Classically, if one has an electron orbiting a proton, how can the magnetic field felt by an observer with the same instantaneous velocity as the electron be calculated? It seems that I may find the magnetic field felt by this observer by boosting the proton to the same frame as... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Recently, I was thinking about fusion and this thought struck my mind. \n\nIn tokamaks, the plasma is heated to extremely high temperatures in order to supply enough energy to the ions for them to fuse. But since, the plasma follows a boltzmann maxwell distribution curve,only a ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "SPACE VELOCITY IN TOLUENE SYNTHESIS\\n\\nThe production of toluene from benzene and xylenes was studied by Johanson & Watson (National Petroleum News, 7 Aug 1946) in a standard 1-inch pipe reactor with a silica-alumina catalyst. At the reaction temperature of 932 F (773 K) the r... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Exactly 850 mL of O2 gas is collected over water at 30.0 °C using the setup below. Given that the barometric pressure was 98.5 kPa and the vapour pressure of water is 4.24 kPa at 30 °C, what volume would the pure O2 gas occupy at 98.5 kPa and 30 °C?\nA 813 mL \nB 818 mL \nC 85... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "It is known that the overall liquid transfer coefficient \\( K_L a \\) for absorption of \\( \\text{SO}_2 \\) in water in a column is 0.003 kmol/s m\\(^3\\) (kmol/m\\(^3\\)). Obtain an expression for the overall liquid-film coefficient \\( K_L a \\) for absorption of \\( \\text{... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "If someone eats chocolate, the chocolate goes through the following configurations:\n$\\chi_0:$ chocolate is solid and has a smooth Surface everywhere; the Riemann Tensor vanishes on every Point of the chocolate, i.e. $R_{\\mu \\nu \\alpha \\beta}=0$.\n$\\chi_1:$ chocolate is so... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "When 1.50 grams of a compound containing only carbon, hydrogen, nitrogen, and oxygen is burned completely in excess O2, 1.72 g CO2, 0.585 g NO, and 1.23 g H2O are produced. What is the empirical formula for the compound?\n\nWhat is the empirical formula for a compound containing... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "To motivate my question, please consider a system with total angular momentum $j$. The fact that the largest eigenvalue of $J_z$ is $j$, while $J^2 = J_x^2 + J_y^2 + J_z^2$ has all eigenvalues equal to $j(j+1)$ is often ascribed to the uncertainty principle.\nFor example, quotin... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Write the structural formulas and give the names of the isomeric methylpyridines."
},
{
"from": "gpt",
"value": "<think> Okay, so I need to figure out all the possible isomeric forms of methylpyridines. Hmm, right, pyridine is a six-membered aromatic ring with a nitr... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I am asking for a book/any other online which has the following quality (To be particular: Of classical physics(Newtonian mechanics, sounds, lights etc, stuff upto 1800's)):\n\nThe book, before introducing any particular theory about any natural phenomena, demonstrates and gives... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "A metal (M) forms a hydrated sulphate, isomorphous with ZnSO4 · 7H2O. If the sulphate contains 20% metal, by weight, which of the following is/are correct for the metal?\\n\\n(a) The atomic weight of metal is 24.\\n(b) The equivalent weight of the metal is 27.75.\\n(c) The metal... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Acid conditions are best for halogenation. Halogenation of carbonyl compounds should be carried out in acid solution. Attempts in basic solution lead to multiple substitutions and C-C bond cleavage. The reason why halogenation in base continues until all the hydrogens have been ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Determine the value of \\( \\Delta G \\) at 25°C for the general reaction\\n\\n \\[\\n 2 \\, \\text{A(aq)} + \\text{B(aq)} \\rightarrow \\text{C(aq)}\\n \\]\\n\\n for which \\( \\Delta G^\\circ = -877 \\, \\text{J} \\), if the A concentration is 0.750 M, the B concentrat... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "In the lecture of my course of Theories of gravity the definition of non-metricity tensor is:\n$$Q(w,v,z)=-\\nabla_{w}g(v,z)+g(\\nabla_{w}v,z)+g(w,\\nabla_{w}z).$$\n\nFirst question: where could i find this definition? I have not found this definition anywhere so far.\n\nSecond ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Consider the hypothetical cyclic phosphonitrilic compound \\([N_4(\\text{PX}_2)_2]\\). After taking care of the \\(\\sigma\\) bonding, it is assumed that the participating atomic orbitals for the \\(\\pi\\) bonds around the ring are the four nitrogen \\(p_\\pi\\) orbitals and tw... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Explanations of shockwave for the common folks (youtube videos, googling) all tend to focus on successive sound waves generated by the air craft traveling outward in circles (sphere).\nThat to me, only explains why the boundary of a sockwave is a straight line (cone). It doesn't... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Take for instance a 4d gauge theory with a fermion $\\psi$ in some representation of the gauge group $G$ and say that I want to study the fate of the \"non ABJ-anomalous\" part of the axial symmetry $U(1)_A$, when going to the IR. Without susy, it is not trivial to know what con... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "In Marcus theory, the activation energy \\( \\Delta G \\) is thought of as consisting of two parts:\n1. An intrinsic free energy of activation, which would exist if the reactants and products had the same \\( \\Delta G^\\circ \\). This is a kinetic part, called the intrinsic bar... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Consider the mechanism for the decomposition of ozone presented in Example 29-5. Explain why either (a) v_1 \\gg v_2 and v_1 \\gg v_{-1} or (b) v_2 \\gg v_{-1} and v_2 \\gg v_1 must be true for the steady-state approximation to apply. The rate law for the decomposition reaction ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Several reactors, each of 25 cuft capacity, are available for conducting the reaction, A + B → Products. These data apply: C_{A0} = 1.5 lbmols/cuft, C_{B0} = 2.25 lbmols/cuft, k = 0.098 cuft/lbmol-min. Required conversion of A is 80%. Find the charge rates for one reactor, three... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "13. Describe simple chemical tests that would distinguish between:\n(g) cyclohexanol and n-butylcyclohexane."
},
{
"from": "gpt",
"value": "<think> Okay, so I have to figure out a simple chemical test to distinguish between cyclohexanol and n-butylcyclohexane. Let me... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "All the vectors here are measured in the inertial frame of reference $I$ .\nNotation used : $O$(origin) is a fixed point in $I$ . $C$ is the center of mass of the rigid body that I am considering and $m$ is its mass.\n$\\mathbf{r_{CA}}$ is the position vector of point $C$ with r... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Aldehydes unite, with the elimination of water, with compounds containing the group CH₂ between two negative radicals (acetacetic ester, malonic ester, acetylacetone, and others), in two ways. One of these ways involves the reaction between one molecule of the aldehyde and two m... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "From the following data, calculate the enthalpy change for the combustion of cyclopropane at 298 K. The enthalpy of formation of CO₂(g), H₂O(l) and propene(g) are -393.5, -285.8 and 20.42 kJ mol⁻¹, respectively. The enthalpy of isomerisation of cyclopropane to propene is -33.0 k... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "EDIT: I was aware of the supposed duplicate. But I'm interested in a clear and focused path through the basics to advanced theoretical physics such as string theory - a path that avoids studying engineering physics - for a pure mathematician with no physics background. I can'... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I have a very naive confusion regarding the propagators of QFT. I have come across the terms:\n\n(i) Retarded propagator,\n\n(ii) Advanced propagator,\n\n(iii) Feynman propagator ...\n\n\nI can comprehend the derivation of these different propagators and how they come to be. How... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Compound\tProton\tNumber of Adjacent Protons\tSplitting\n\n(c)\tClCH2CH2CH2Cl\t1 2\t2 4\ttriplet\nquintet\n\nFor the compound ClCH2CH2CH2Cl, what is the proton splitting pattern and the number of adjacent protons?"
},
{
"from": "gpt",
"value": "<think> Okay, let me t... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "NH₃ + O₂ → NO + H₂O. When the following equation is balanced using the smallest whole number coefficients, what is the coefficient of O₂? \n* A 2 \n* B 3 \n* C 4 \n* \\*D 5 \n* E 6 "
},
{
"from": "gpt",
"value": "<think> Okay, so I have to balance the... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Boundary $S$ of a cavity in a very large (perfect) conductor is a connected compact (smooth) surface. A positive point charge $+q$ is placed inside this cavity. From Gauss' law we know that the total induced charge on the surface $S$ is $-q$. However, is the surface charge dens... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "The available experimental data prefers plateau models of cosmic inflation, and among them Starobinsky inflation (aka R^2 inflation) is preferred, even if maybe not significantly. See here for summary and pointers.\nSince Starobinsky inflation is pure gravity (the inflaton field... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Given some total system $ H = H_A \\otimes H_B$, we can find the entanglement entropy for a subspace by taking $S = -tr(\\rho_A ln \\rho_A)$ with $\\rho_A = tr_B \\rho$, where $\\rho$ is the density matrix of the system. For a two particles in a two level system (i.e. a state ca... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Replacement of a proton by CH3 results in a downfield shift of approximately 8 p.p.m. at C-1, and approximately 10 p.p.m. at C-2, while causing an upfield shift at C-3 of about 2 p.p.m. Polar substituents result in a downfield shift in the position of absorption. What effect doe... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "\\[\\n\\frac{1}{2\\pi i} \\int_{C_1} \\frac{e^{zt}dz}{z(1-e^{-az})} \\quad (a > 0).\\]\\n\\n**Hint.** Make use of the expansion \\n\\n\\[\\n\\frac{1}{1-e^{-az}} = 1+e^{-az}+e^{-2az}+\\ldots\\]"
},
{
"from": "gpt",
"value": "<think> Okay, so I need to compute this con... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "(a) Determine the pH of a 0.10 M solution of pyridine, \\( C_5H_5N \\). (b) Predict the effect of addition of pyridinium ion, \\( C_5H_5NH^+ \\), on the position of the equilibrium. Will the pH be raised or lowered? (c) Calculate the pH of 1.00 L of 0.10 M pyridine solution to w... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Cyclohexene, C6H10, decolorizes an aqueous solution of potassium permanganate and unites with bromine to form dibromohexamethylene: \nC6H10 + Br2 = C6H10Br2. What does the reaction of cyclohexene with bromine produce?"
},
{
"from": "gpt",
"value": "<think> Okay, let... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I am a computer graphics guy in the area of physically-based rendering and recently I've been searching on the net to figure out how physical is Physically Based Rendering (PBR). The nature of the question lies somewhere between pure physics and pure graphics, so I'm hoping I fi... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I'm following the notes \"Ginsparg - Applied Conformal Field Theory\" (https://arxiv.org/abs/hep-th/9108028) and I'm stuck on a proof at page 140 about Kac-Moody algebras.\nI would like to prove that $\\beta = 2\\tilde{k} +C_A$ using the given definition of the stress-energy ten... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "The singlet at 8.7 ppm is the only signal in the spectrum that can be attributed to the proton of the OH group. Because the signal integrates to 2 protons, the compound must have two OH groups in the same environment. What does the singlet at 8.7 ppm, which is the only signal in... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "(a) CH3 > SO3H > NO2 - (B) Stability of σ-complex"
},
{
"from": "gpt",
"value": "<think> Okay, so I have to tackle these two parts: part (a) which is about the order of stability of some substituents in a sigma complex, and part (b) which is about the stability of th... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "The solubility of Mg(OH)₂ in pure water is \\(9.57 \\times 10^{-3}\\) g L⁻¹. Calculate its solubility (g L⁻¹) in 0.02 M Mg(NO₃)₂ solution. (1986)"
},
{
"from": "gpt",
"value": "<think> Okay, so I need to calculate the solubility of magnesium hydroxide, Mg(OH)₂, in a ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Why is splitting observed in 2-methylpropene but not in 1-chloro-2,2-dimethylpropane?"
},
{
"from": "gpt",
"value": "<think> Okay, so I need to figure out why splitting is observed in 2-methylpropene but not in 1-chloro-2,2-dimethylpropane. Hmm, splitting in NMR? I t... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Two isomeric triglycerides are hydrolyzed to 1 mol of C_{17}H_{35}COOH (A) and 2 mol of C_{17}H_{35}COOH (B). Reduction of B yields n-stearyl alcohol, CH_3(CH_2)_{16}CH_2OH. Compound A adds 1 mol of H_2 to give B and is cleaved with O_3 to give nonanal, CH_3(CH_2)_7CH=O, and 9-o... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "One of the postulates of quantum mechanics is that, given a quantum state $\\psi_{0}$ at time $t=0$, the state of the system at a posterior time $t > 0$ is given by $\\psi_{t} = e^{-iHt}\\psi_{0}$, where $H$ is the Hamiltonian operator of the system.\nThe operator-valued functio... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "The reaction in a given direction is spontaneous if the change in Helmholtz Function, A, is negative at: (a) constant P and T (b) constant V and T (c) constant H and S (d) constant T and S."
},
{
"from": "gpt",
"value": "<think> Okay, let's try to figure out this the... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I want to calculate the magnetic scalar and vector potentials for an infinite axial current density given as\n\\begin{equation}\nJ(r,\\varphi) = \\frac{I}{R} \\delta(r-R) \\sin\\varphi \\cos\\varphi \\bf{\\hat{k}}.\n\\end{equation}\nFor the vector potential, I think I need to g... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Which of the following is incorrect statement?\\n (a) The packing efficiency of SiC is greater than that of diamond.\\n (b) The coordination number of Si and C-atoms in SiC is same.\\n (c) The number of C–C bonds per unit cell in diamond is 16.\\n (d) The coordination nu... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "2. The biosynthesis of fatty acids is accomplished with two carbons at a time by an enzyme complex called fatty acid synthetase. The biochemical reactions involved in fatty acid synthesis are described in Special Topic G (WileyPLUS). Each of these biochemical reactions has a cou... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I have some questions regarding the quantum Zeno effect (QZE). It is known that this effect occurs, when a system interacts strongly to its environment (one says that there are done measurements extremely frequently). In the opposite case, if no interaction with environment tak... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "The enzyme carbonic anhydrase is one of the speediest enzymes known. It catalyzes the hydration of \\(\\text{CO}_2\\) to \\(\\text{H}_2\\text{CO}_3\\), which then rapidly dissociates as described in Problem 2-57. Carbonic anhydrase accelerates the reaction \\(10^7\\)-fold, hydra... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Suppose I want to represent the quantum state of a spinless particle. To do so, I employ a Hilbert space $\\mathcal{H}_X$, which is an infinite-dimensional Hilbert space equipped with a position operator $\\hat{X}$. If I want to represent the quantum state of a spin-1/2 particle... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Exercise 4.19\\n\\nMichael Crichton in the *Andromeda Strain* (1969) states that “A single cell of the bacterium *E. coli* would, under ideal circumstances, divide every twenty minutes... It can be shown that in a single day, one cell of *E. coli* could produce a super-colony eq... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "As can for example be learned from chapter I.2 of Anthony Zee's Quantum field theory in a nutshell, path integrals can be used to to calculate the amplitude for a system to transition from one state to another by considering all possible paths between the two states.\nThis artic... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Mean field theory applied to spin-chains, where the ground state is assumed a product state and the energy is variationally minimized, is one of the tools in my toolkit. The examples I give in this question make me wonder if it behaves inappropriately under the addition of quart... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Mention the products formed in the following: (i) Zinc oxide is treated with excess of sodium hydroxide solution. (ii) Iodine is added to a solution of stannous chloride. (iii) Sulphur dioxide gas, water vapor, and air are passed over heated sodium chloride. (IIT-JEE, 1986)"
}... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "\nI want to calculate the eigenfrequencies of a 3D truss using the finite element method. The beams should be modelled as Timoshenko beams and I want to use arbitrary shape functions.\n\n\nI know how to use the finite element method to solve equations of the form $a(u,\\bar{u}) ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Draw the structure of (1R, 2S)-[^2H] cyclohexylamine and carry out Cope elimination after the necessary modification of the compound. What would be the product when diastereomeric (1R, 2S)-isomer is subjected to similar reactions?"
},
{
"from": "gpt",
"value": "<thin... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "There are two procedures that I know of for finding the von Neumann entanglement entropy of a bipartite system split between $A$ and $B$ - a bad way and a better way. I have in mind computationally calculating the entanglement entropy for a spin chain of even length $L$.\nThe b... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "What is the highest electric field known in nature?\nTo add clarity, as requested: an electric field is measured in V/m, Volt per meter.\nWhat is highest value that has been measured or observed?\nWhat is the highest value that is suspected?\nThere are two candidates situations ... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Let $\\mathcal N^{A_1\\rightarrow B_1}_1,..,\\mathcal N^{A_1\\rightarrow B_1}_k$ be a set of valid quantum evolutions with equal input and output dimensions. And let the effect of a channel on a system $\\rho_{A_1A_2}$ be: \n$$\\mathcal N^{A_1A_2\\rightarrow B_0B_1}(\\rho_{A_1A_... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Lithium iodide crystallizes in the NaCl lattice despite the fact that r+/r- is less than 0.414. Its density is 3.49 g/cm3. Calculate from these data the ionic radius of the iodide ion."
},
{
"from": "gpt",
"value": "<think> Okay, so I have this problem about lithium ... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Assume we have a system with particle density $n$, such that $n$ fulfils the diffusion equation with $D$ as the diffusion coefficient. Initially $n(\\vec{r}, t=0) = n_0\\delta^3(\\vec{r})$, which implies\n$$\nn(\\vec{r}, t) = \\frac{n_0}{(4 \\pi Dt)^{3/2}} \\exp \\left(-\\frac{r... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "It might be a silly question, but I really don't know. There're 3 things I want to ask:\n\nFor example, with Schrödinger's equation $i\\partial_{t}\\psi = H\\psi$ , where $\\psi_{n}(x)$ are the eigenfunctions of $H$, what does it mean to apply a Fourier transformation on $\\psi_... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "In the hydroxide-ion-promoted hydrolysis of a series of ethyl benzoates, electron-withdrawing substituents increase the rate of the reaction by increasing the amount of positive charge on the carbonyl carbon, thereby making it more readily attacked by hydroxide ion. The p value ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "What are hormones regulating glycolysis?"
},
{
"from": "gpt",
"value": "<think> Okay, so I need to figure out which hormones regulate glycolysis. Hmm, glycolysis is the process of breaking down glucose to produce ATP, right? And hormones influence various metabolic p... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Consider two long wire with negligible resistance closed at one end of the resistance R (say a light bulb), and the other end connected to a battery (DC voltage). Cross-sectional radius of each wire is in $x = 100$ times smaller than the distance between the axes of the wires.\... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "*p*-Chloronitrobenzene was allowed to react with sodium 2,6-di-tert-butylphenoxide with the intention of preparing the diphenyl ether 1. The product was not 1, but rather was an isomer of 1 that still possessed a phenolic hydroxyl group.\\n\\n### Structure:\\n\\[\\n\\ce{C(CH3)3-... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Equivalence principle tells us that for a freely falling inertial observer spacetime is locally flat. The coordinate transformation needed to introduce Locally Inertial Coordinates were discusses in this response. However, I have studied in general relativity that no coordinate ... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "A gas producer uses coal of the following composition:\\n\\n | Component | Per Cent |\\n |-----------|----------|\\n | C | 76 |\\n | H | 3 |\\n | O | 6 |\\n | H₂O | 3 |\\n | Ash | 12 |\\n\\... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "For the reversible reaction: \\text{A} \\rightleftharpoons \\text{B}, the time at which the rate of change in concentration of ‘A’ is equal to the rate of change in concentration of ‘B’ is/are (a) t = 0 (b) t = t_{1/2} (c) t = t_{\\text{equilibrium}} (d) t = \\text{infinite}"
... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "In problem 8.1 of Hatfield's Quantum Field Theory of Point Particles and Strings, the reader is tasked with calculating the trace $$\\operatorname {tr}(\\gamma_0\\frac{(\\not p_2 + m)}{2m}\\gamma_0\\frac{(\\not p_1 +m)}{2m}).\\tag{problem 8.1}$$ Hatfield says that one should obt... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "I'm trying to understand tension. So here it goes:\nI'll start from the beginning.\nLet's assume I'm in space and can move around and apply forces.\nLet's say a rope is attached to a body(which is in space).\n1) Let's say the body is immovable.\nThen the force with which the rop... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Zeisel determination was developed by the Austrian-Czech chemist Zeisel to determine the number of methoxy and ethoxy groups in a molecule before spectroscopic techniques became available. The method was as follows: 1. A known mass of the compound of interest is combined with an... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Ascorbic acid (vitamin C) is a diprotic acid, \\( \\text{H}_2\\text{C}_6\\text{H}_6\\text{O}_6 \\). What is the pH of a 0.10 M solution? The acid ionization constants are \\( K_{a1}=9.0 \\times 10^{-5} \\) and \\( K_{a2}=1.6 \\times 10^{-12} \\). (log 2 = 0.3, log 3 = 0.48). (a)... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "All the derivations of the Schwinger-Dyson equation I can find are done using either the path integral formalism, or for the oldest papers, Schwinger's own quantum action principle formalism, which, while it resembles the Heisenberg formalism, assumes that the operator derived i... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "When I was studying Classical Mechanics, particularly Lagrangian formulation and Hamiltonian formulation. I always wondering how to understand the meaning of independence of parameters used of describing motion of object? For instance, we have the generalized coordinates and gen... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "In which of the following will cis-3-hexene differ from trans-3-hexene? \n(a) b.p. \n(b) m.p. \n(c) adsorption on alumina \n(d) infrared spectrum \n(e) dipole moment \n(f) refractive index \n(g) rate of hydrogenation \n(h) product of hydrogenation \n(i) solubility in et... |
null | stackexchange-physics | science | [
{
"from": "human",
"value": "Classically, if one has an electron orbiting a proton, how can the magnetic field felt by an observer with the same instantaneous velocity as the electron be calculated? It seems that I may find the magnetic field felt by this observer by boosting the proton to the same frame as... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "The electron-withdrawing property of the 2,4-dinitrophenyl group makes separation of the labeled amino acid very easy. Suggest how this is done."
},
{
"from": "gpt",
"value": "<think> Okay, so I need to figure out how the electron-withdrawing property of the 2,4-dini... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "Another good method for the preparation of this ether is the acid-catalyzed addition of ethanol to 2-methylpropene. What is another good method for the preparation of the ether described?"
},
{
"from": "gpt",
"value": "<think> Okay, so I need to figure out another me... |
null | organic-chemistry-questions | science | [
{
"from": "human",
"value": "What volume of 5.00 N HCl is needed to prepare 12.7 liters of \\( \\text{CO}_2 \\) at 735 torr and \\( 35.0^\\circ \\text{C} \\)? (CaCO\\(_3\\) is used as the source of \\( \\text{CO}_2 \\).)"
},
{
"from": "gpt",
"value": "<think> Okay, so the problem is asking me to... |