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Na 23, Cl 35.5 density of water 1g cm3 2marks b Water containing hydrogen carbonate, HCO3-and calcium ions, Ca2 is said to be hard. Explain how these ions get into sources of water. 2marks www.freekcsepastpapers.comPage 103 c Analysis of river water sample showed the presence of the following ions: Mg2 , Na , Cl , 24SO... |
Study it and answer the questions that follow. I Write an equation for the reaction in the absorption chamber 1mark ii Explain how the acid is obtained after the reaction in the absorption chamber 1mark iii State two roles of the heat exchanger 2marks iv How is pollution controlled in the above process 1mark www.freekc... |
A Use the following data to calculate the enthalpy change for the decomposition of calcium carbonate Ca s O2 g Ca O s H -635kJmol-1 Ca s C s 3 2O2 g Ca CO3 s H - 1207kJ mol C s O2 g CO2 g H -394kJ Mol 2marks b State two factors to consider when choosing a fuel 1mark c The diagram below represents a set up used to deter... |
MgCl2 s Mg2 g 2 Cl- g H 2487kJ mol. MgCl2 s aq Mg Cl2 aq H2 -170 kJ mol 2Cl- g aq 2Cl- aq H3 -762kJ mol a Name the enthalpies H1 and H2 1mark b Determine the enthalpy for the reaction 2marks Mg2 g aq Mg 2 aq 7. A Study the flow chart below and use it to answer the questions that follow. Results: Initial water temperatu... |
MgCl2 s aq Mg Cl2 aq H2 -170 kJ mol 2Cl- g aq 2Cl- aq H3 -762kJ mol a Name the enthalpies H1 and H2 1mark b Determine the enthalpy for the reaction 2marks Mg2 g aq Mg 2 aq 7. A Study the flow chart below and use it to answer the questions that follow. Results: Initial water temperature 22.00C Final water temperature 44... |
A Study the flow chart below and use it to answer the questions that follow. Results: Initial water temperature 22.00C Final water temperature 44.50C Mass of lamp before burning 126.5g Mass of lamp after burning 125.0gwww.freekcsepastpapers.comPage 105 I Name: R, S and T 3marks II Write the chemical equation for the re... |
B ALL working MUST be clearly shown where necessary. C Mathematical table and silent electronic calculators may be used. 1. You are provided with: i Solution P which is a monobasic acid solution. Ii 2cm long magnesium ribbon labelled metal M. iii 0.5M sodium hydroxide solution Q You are required to: a Calculate the mas... |
The diagram below shows part of the Frasch process used for extraction of sulphur. Use it to answer the questions that follow. A Identify X 1mk b Why is it necessary to use superheated water and hot compressed air in this process? 1mk c State two physical properties of sulphur that makes it possible for it to be extrac... |
How will increase in pressure affect the yield of nitrogen II oxide? 1mk 20. After 7.5 hrs the percentage of a certain nuclide in a sample of ore was found to be 12.5 . A What is meant by the term half-life? 1mk b Determine the half-life of the nuclide. 2mks 21. Name the following compound. Ii. CH3 COOCH2CH2CH3 1 mk b ... |
Name the catalyst Y. 1mk II. State one commercial use of sulphuric VI acid. 1mk d i. The copper obtained from the chamber N is not pure. Draw a labelled diagram to show the set up you would use to refine the copper by electrolysis. 2mks ii. Given that the mass of copper obtained from the above extraction was 210kg. Det... |
Www.freekcsepastpapers.comPage 124 a i Write an equation for the reaction that took place. 1mk ii. Explain why there is loss in mass. 1mk b Sketch on the same axes, the curve obtained when: I: Same mass of zinc powder was used under the same conditions. Label it P. 1mk II: No catalyst was used. Label it N. 1 mk c In th... |
1mk ii. During the reaction in c i above, 6.30g of iron II chloride were converted to substance E. Calculate the volume of chlorine used. 3mks Cl 35.5, Molar gas volume at room temperature 24000cm3, Fe 56 d Draw and name the structure of the compound formed when excess chlorine gas is reacted with ethane gas. 2mks e Gi... |
8. A 25ml pipette. 9. A thermometer -100C 1100C 10. Stopwatch. 11. About 15cm3 of liquid Q. 12. Watch glass. 13. Test tube holder. 14. 0.1g NaHCO3. 15. A dropper. 16. 1g ammonium iron II sulphate hexahydrate. Labelled solid T NH4 2 SO4FeSO4.6H2O 17. 500cm3 distilled water in a wash bottle. 18. Metallic spatula. 19. One... |
1 mk b Given that the equation for the reaction between solution Y and X is: MnO- 4 aq 8H aq 5Fe 2 aq Mn2 aq 5Fe3 aq 4H2O l Determine i. The number of moles of iron II salt, solution X in 25cm3 of the solution used. 1 mk ii. The concentration of solution X in moles per litre. 1 mk iii. The relative formula mass of the ... |
Give one reason why they have low melting points. 1 mark 3. A heavy metal P was dissolved in dilute nitric acid to form a solution of compound P NO3 2. Portions of the resulting solution were treated as follows: i To the first portion a solution of dilute hydrochloric acid is added, where a white precipitate S is forme... |
The diagram below represents an experiment which was carried out by a student, to investigate the effect of passing an electric current on molten sodium chloride. I . Molten sodium chloride is a binary electrolyte. State the meaning of the term binary electrolyte. 1 mark ii . State two observations made at the anode 1 ... |
A State the importance of light in the above reaction. 1 mark b Write an equation for the reaction that occurs once the mixture is exposed to light.1mark c Name the organic product formed in the above reaction 1mark 10. Below is an equation showing an equilibrium Br2 aq H2O l Br aq 2H aq OBr aq State and explain the ob... |
3.78g of a hydrated salt of iron II sulphate, FeSO4, in H2O were heated until all the water of crystallization was driven off. The anhydrous salt left had a mass of 1.52g. Determine the formula of the hydrated salt. Fe 56, S 32, H 1, O 16 3 marks 16. A steady current of 0.2 Amperes was passed through molten silver brom... |
Give a reason for your answer 1020 40 60 80 100 120 140Salt ASalt BSolubility g per 100g of H o2Temp C 0DryChlorine gasDrying agent MIron wireSolid Pwww.freekcsepastpapers.comPage 140 18. A radioactive cobalt Co6128 undergoes decay by emitting a beta particle and forming Nickel atom, a Write a balanced decay equation f... |
Explain. 2mark www.freekcsepastpapers.comPage 141 22. Study the set up below and answer the question that follows a Write an equation for the reaction which takes place in the combustion tube. 1mark b What property of gas Z to allows it to be collected as shown in the diagram . 1mark c Identify gas Z 1mark 23. The setu... |
Study it and answer the questions that follow. The letters are not the actual symbol of the elements. Q X B H M T Y A V Z S a Select the least reactive non-metal. 1mk b Which of the elements has the greatest tendency of forming covalent compounds in nature? Explain your choice. 1mk c Explain why the atomic radius of T ... |
An experiment was carried out using magnesium ribbon and dilute hydrochloric acid of different concentrations. The time needed to produce 50cm3 of the gas for every experiment was recorded in a table. Concentration of HCl moles per litre 2.0 1.75 1.50 1.25 1.00 0.75 0.50 0.25 Time seconds 8.8 10.0 11.7 14.0 17.5 18.7 3... |
1mk ii What is the identity of metal F. 1mk iii State the name of the ore from which metal F is extracted. 1mk iv Explain why the metal loses its lustre when exposed to air. 1mk v What is the function of wire gauze shell that separates the anode from the cathode? 1mk vi Write a chemical equation for the reaction betwee... |
11. 400cm2 of distilled water. 12. Means of labeling. 13. About 0.5g of NaHCO3 Solid A. 14. 5cm3 of solution D. 15. About 1g of solid R. 16. Bunsen burner. Access to: 2M aqueous ammonia solution supplied with a dropper. Phenolphthalein indicator supplied with a dropper. 0.5M KI solution. 2M HCL 2M NaOH Zinc granules. 0... |
Mk . Iii How does the melting point of A compare with that of E? Mk . Iv 2.6 g of B reacts completely when heated with 2.42 litres of chlorine gas Cl2 at s.t.p, calculate the relative atomic mass of B. 1 mole of gas occupies 22.4 litres at s.t.p. 112mk . 5. Explain the differences in bleaching properties of chlorine an... |
A solution of bromine in water is a chemical reaction in equilibrium. The reaction involved is represented by the equation below; Br2 aq H2O l 2H aq Br- aq OBr- aq Yellow Colourless i State and explain the observation made when dilute sulphuric VI acid is added to the mixture at equilibrium. 2mks ii Define the term dyn... |
Briefly describe how caffeine can be extracted from tea leaves. 3mks 17. State the two roles of platinized-platinum in a standard hydrogen electrode 2mks 18. Explain the following 3mks i Yellow phosphorus is stored under water ii Sodium is stored under paraffin oil iii Lime water and not potassium hydroxide is used to ... |
The structure of RCOO-Na below represents a type of cleansing agent. Describe how the cleansing agent removes grease from a piece of cloth. 3mks 23. The diagram below represents a jiko when in use. Study it and answer the questions that follow. I Write equations for the reactions that occur in region I: B 1 mk II: C 1 ... |
Explain. 2 marks c An element X forms an ion with the formula X2 . The electronic configuration of the ion is 2.8 i State the group and period to which element X belongs. 1mark Group .. . Period ii Draw dot and cross diagram showing bonding when X combines with chlorine 1 mark d Explain the following observations; i Ca... |
A 2 aq 2e A s 0.34 V N 2 aq 2e N s 0.76 V G aq 2e G s 0.00 V Y 2 aq 2e Y s 0.88 V L 2 aq 2e L s 2.16 V i Identify the strongest reducing agent 1 mark ii Explain why a solution containing A2 ions cannot be stored in a container made of metal N 1 mark iii The half cells of Y and L were combined to form an electrochemical... |
I Draw a well labelled diagram of the cell formed 3 marks II Calculate the e.m.f of the cell formed above 1 mark c The diagram below shows the set up used to investigate electrolysis of dilute sulphuric VI acid solution i Identify product X and Y 1 mark ii Write an equation for the reaction at the anode 1 mark iii Expl... |
Describe three successive tests he would carry out to confirm the solid is zinc and give the observations expected in each test. 3marks Test Procedure Expected observation 1 2 3www.freekcsepastpapers.comPage 171 7. The diagram below shows the laboratory preparation of ammonia gas. Study it and use it to answer the ques... |
Phenolphthalein indicator 2. Source of heat 3. 2M Pb NO3 2 aq 4. 2M HNO3 aq 5. 0.5M Ba NO3 2 aq 6. 2M Ammonia solution 7. 2M NaOH 8. Acidified KMnO4 solution 9. 2M HCl aq NOTES 1. Solution Q is 0.05M oxalic acid 2. Solution P is 0.01M potassium manganate vii solution. 3. Solution R is 0.1M sodium hydroxide solution. 4.... |
1mk 4. The table below gives information on four elements by letters K, L, M and N. Study it and answer the questions that follow. The letters do not represent the actual symbol of the elements. Element Electron arrangement Atomic radius nm Ionic radius nm Q 2.8.2 0.136 0.065 R 2.8.7 0.099 0.181 S 2.8.8.1 0.203 0.133 T... |
A Explain how a sample of CH3CH2OH could be distinguished from a sample of CH3COOH by a chemical test 2mks b Give the name of the type of compound formed when the a above are reacted . 1mk 8. A polymer has the following structure a Draw the repeating unit of the polymer 1mk b A sample of this polymer is found to have a... |
M grammes of a radioactive isotope decayed to 5 grammes in 100 days. The half life of the isotopes is 25 days. A What is meant by half life? 1mks b Calculate the initial mass M of the radioactive isotope 2mks 14. Complete the diagram to show how a sample of dry ammonia gas can be prepared in the laboratory. 3mks 15. 30... |
2mks 27. In an experiment to study the properties of concentrated nitric acid, a mixture of the acid and wood charcoal was heated in a boiling tube. A What observations were made? Explain your answer 2mks b Write an equation for the reaction that took place in the boiling tube 1mk www.freekcsepastpapers.comPage 191 MUM... |
Explain. 2mks iv The melting point of E and K are 1120oC and -34oC respectively. In terms of structure and bonding, explain why there is a large difference in the melting point of E and K. 2mks v Indicate on the grid the position of element L which forms L3- ions with electronic configuration 2.8.8. 1mk vi Element J re... |
A Identify the following substances 2mks i Solid A ii Gas D. iii Solid Q. iv Solution M. b Write a chemical equation for the reaction in step I. 1mk c Write chemical equation for the formation of the following compounds. 3mks i Solid G. ii Gas D. iii Light blue solution C. iv State the confirmatory test for oxygen gas.... |
Add 2 drops of phenolphthalein indicator and titrate with solution B. Record your results in table 1 below. Repeat the titration two more times and complete the table. Table 1 4marks I II III Final burette reading cm3 Initial burette reading cm3 Volume of solution B used cm3 a Determine the average volume of solution B... |
Filter funnel 3. Pipette 25cm3 4. One pipette filler 5. 0.3g of solid G 6. Two 250ml conical flasks 7. About 120ml of solution A 8. About 100ml of solution B 9. About 60ml of solution C 10. About 100ml of solution D 11. One 10ml measuring cylinder 12. Thermometer -10 110OC 13. 100ml plastic beaker 14. Two boiling tubes... |
100cm3 of oxygen diffuse through an opening in 10 seconds while 150cm3 of unknown gas takes 12 seconds. Calculate the molecular mass of gas x. O 16.0 3mks 6. In a titration experiment 25cm 3 of sodium hydroxide solution containing 8.0g per litre was required for complete neutralization of 0.245g of diabasic acid. Calcu... |
Use the information to answer the questions that follow. Element 1st ionization energy kJ Mol A1 500 A2 420 A3 400 A4 520 i. What is meant by the term ionization energy? 1mk ii. Select the most reactive element. Give a reason for your answer. 1mk iii. Arrange the element according to increase in atomic radii. 1mk 12. A... |
1 mk ii. The relative molecular mass of K is 15680. Calculate the number of monomers that make up K. 1mk 18. Below is a flow chart that shows the process of obtaining substance C from ammonia gas at an optimum temperature of 9000C and in presence of a catalyst. A Name raw materials used in Haber process. 1mk b Identify... |
The table below shows the relative molecular masses and the boiling points of; Explain why the boiling point of butan 1 ol is higher than that of butane. 2mks 24. Study the thermochemical equations below and answer the questions that follow. C s O 2 g ----- CO 2 g H C -39.3kJ Mol H 2 g O 2 g ------ H2O g H C - 286kJ Mo... |
Describe the chemical tests that would distinguish between C3H8O and C2H4O2. 2 mks 29. Study the information given in the table below and answer the questions that follow. Half reactions Electrode potential E V P 2 aq 2e - P s 0.34 Q aq e- Q s 0.80 R 2 aq 2e- R s -2.87 V 2 aq 2e- V s -0.13 W 2 aq 2e- W s -2.71 U3 aq e-... |
Write a balanced equation for the reaction between Q and R. 1mk II. Determine the R.A.M of Q Molar Volume of a gas at s.t.p 22.4dm3 2mks b Study the information given below and answer the questions that follow. Formula of compound Nacl MgCl2 Al2Cl6 SiCl4 PCl5 Boiling point 0C 1470 1420 Sublimes 60 75 Melting point 0C 8... |
Chlorine reacting with Iron. 1mk II. Chlorine reacting with hot concentrated sodium hydroxide solution. 1mk iv An oxide of chlorine of mass 1.83g was found to contain 1.12g of oxygen. Determine the empirical formula of the oxide. O 16, Cl 35.5 3mks v Other than manufacture of hydrochloric acid name two other uses of ch... |
Letters do not represent the actual symbols of the elements. Half cell E value V F2 aq 2e- 2F- aq 0.54 G2 aq 2e- G s -0.44 H2 aq 2e- H s 0.34 2J aq 2e- J2 g 0.00 i Identify the strongest reducing agent. Explain. 1mk ii Write the equation for reaction which takes place when solid G is added to a solution containing H2 a... |
The mixture was stirred with a thermometer and the temperature noted. The temperature rose from 220C to 28.20C and 1.58g of Copper was deposited. A Write ionic equation for the reaction that took place. 1mk b Why was excess Zinc powder used? 1mk c Besides the temperature rise state two other observations made as the mi... |
I Describe how the car bon content is reduced. 2mks ii Why is it necessary to reduce the carbon content? 1mk www.freekcsepastpapers.comPage 221 KIRINYAGA WEST SCHOOL BASED EXAMINATION, 2023 233 3 CHEMISTRY PAPER 3 CONFIDENTIAL In addition to the sittings and apparatus found in a chemistry laboratory, each candidate wil... |
Solution T is 0.15M sodium thiosulphate. 6. Solid M is 3 cm polished magnesium ribbon. Www.freekcsepastpapers.comPage 222 KIRINYAGA WEST SCHOOL BASED EXAMINATION, 2023 233 3 CHEMISTRY PAPER 3 Practical TIME: 2 HOURS 15 MINUTES Instructions to candidates a. Answer ALL the questions. B. Mathematical tables and electronic... |
A Explain the role of common salt in defrosting ice on roads in ice cold countries. 1 mark b Explain why the long-term effects of use of common salt is costly to motorists. 1 mark 13. Given the equation below NH3 aq H2O l NH4 aq OH- aq Identify the species that acts as; H HHHwww.freekcsepastpapers.comPage 234 i A base.... |
2 marks c Given that HC C - 393kJmole-1, HC H2 -286kJmole-1 and HC C2H5OH - 1368kJmole-1. Calculate the enthalpy of formation of C2H5OH. 2 marks 19. 3.78g of a hydrated salt of iron II sulphate, FeSO4, in H2O were heated until all the water of crystallization was driven off. The anhydrous salt left had a mass of 1.52g.... |
Mark b What would be the importance of heating the ore first before refining it? 1 mark c The refined ore has to be dissolved in cryolite first before electrolysis. Why is this necessary? 1 mark d Why are the carbon anodes replaced every now and then in the cell for electrolysing aluminium oxide? 1 mark 23. Use the cel... |
B The second portion is treated with two drops of 2M Sodium hydroxide solution where a white precipitate T is formed. The white precipitate dissolved in excess sodium hydroxide to form a colourless solution. C A solution of potassium iodide is added to the third portion where a yellow precipitate U is formed. D When th... |
State how the two substances differ as conductors of electric current. 2marks 2. Study the flow chart below and answer the questions that follow. Www.freekcsepastpapers.comPage 238 R CONa O a Name ore N 1mark b Explain why the ore is first dissolved in excess sodium hydroxide solution. 1mark c Name the major compound p... |
The standard reduction potentials for five half cells are shown in the table below. Study it and answer the questions that follow. The letters do not represent the actual symbol of elements . Elements E Volts i 09.1 aqaqAeA ii 13.022 SaqQeQ iii 37.222 SaqReRwww.freekcsepastpapers.comPage 239 iv 34.022 SaqYeY v 00.0222 ... |
1mark b List TWO sources of obtaining large volumes of hydrogen for industrial use. 2 marks c Write equation for Haber process. 1mark d Name the catalysts for: 1mark i Haber process ii Contact processwww.freekcsepastpapers.comPage 240 e Identify substances: 1mark i D . Ii C . F Give ONE major use of compound D 1mark g ... |
Repeat procedure II three more times and record the temperatures in table 1. RETAIN the contents of the boiling tube for use in PROCEDURE II. TABLE 1 Volume of water in the boiling tube cm3 Crystallization temperature C Solubility of solid P in g 100 g of water 4 6 8 10 12 4marks a Complete table 1 above by working out... |
Place all solid E into a boiling tube. Add about 20cm3 of distilled water and shake. Retain the contents of the boiling tube. Observations inferences 1 mark 1 mark Use 2cm3 of solution E, in a test tube in each experiment i, ii, iii, iv and v i. To experiment i, Add two drops of aqueous Sulphuric vi acid Observations i... |
Hydrogen sulphide gas was bubbled through a solution of zinc nitrate for some time. I State the observation made. 1mark ii Where should the experiment be carried out and why? 1mark iii Write the equation of the reaction that occurs 1mark 25. 25cm3 of 0.12M Potassium Hydroxide solution required 30cm3 of a solution of a ... |
The flow chart given shows an analysis of mixture K that contains two salts. Study it and answer the question that follows. A Name substances L, M and N 1 marks b What condition is necessary for step 1 to take place? 1mark c State the colour changes that the metal oxide undergoes when hot and cold 1mark d Write down an... |
1mark iv Name liquid B 1mark b Consider the following reaction: N2 g 3H2 g 2NH3 g H 75KJ Sketch an energy level diagram showing the relative activation energies for the catalysed and uncatalysed reactions using the axes below. 2 marks Energy KJ Reaction path c Given that the lattice energy of calcium chloride is 2237kJ... |
Study the table below and answer the questions that follow. The letter do not represent the actual symbols of the elements Element A B C D E F G H Atomic number 11 12 13 14 15 16 17 18 Boiling point 0c 890 1110 2470 2360 280 445 -34.2 -186 Formula of Oxide BO E2O5 G2O Boiling point of oxide of 0c 1193 3075 2045 1728 56... |
1mk b i Draw a diagram to show how an aluminium spoon can be electroplated with copper. 2 marks ii In the experiment to electroplate aluminium spoon, 0.2 amperes were passed through the solution for 1,930 seconds. The mass of the aluminium spoon increased from 6.35 to 6.478 g. Find the charge on a copper ion. 1 Faraday... |
C7H16 11O2 7CO2 8H2O, H -4800Kj I. What mass of carbon IV oxide would be produced when 5g of C7H16 were burned? C 12, H 1, O 16 2mks II. Draw the structural formula of 3,3-dimethylpentane. 1mk b Perspex is a synthetic polymer formed from the monomer below. I Draw a polymer with three repeat units. 1 mark ii A sample of... |
Solid Q 1g Na2 CO3 : PbCO3 1:2 17. Solid M. Crushed paracetamol.1 tablet per candidate ACCESS i 2M HNO3 ii 2M HCl iii 2M NH3 iv Acidified KMnO4 v Acidified K2Cr2O7 vi Bromine vii Source of heat viii Tripod stand ix Wire gauze NOTES a. Solution B 0.04 M acidified KMNO4 b. Solution A Ferrous ammonium sulphate Fe SO4 NH4 ... |
1 mark ii The concentration of solution A in moles per litre 1 marks iii The concentration of solution A in grams per litre 1 marks iv The relative formula mass of iron II salt 1 marks v The value of X in the formula FeSO4. NH4 2 SO4.XH2O Fe 56, N 14, S 32, O 16 1 mark b You are provided with 2.0 M sulphuric vi acid la... |
Record the time taken in the table below in each case. Vii Complete the table by calculating the reciprocal of time 1 t Temperature of the solutions 0c 65 60 55 50 45 Time taken for the purple colour to disappear s 1 t sec- 5mks I. Plot a graph of 1 t y axis against the temperature at the point when the solution become... |
KNEC Mathematical tables and silent non-programmable electronic calculators may be used. 3. All working MUST be clearly shown where necessary 1. A Explain the condensation process using the kinetic theory of matter. 1mk b Name one chemistry laboratory apparatus that can be used to measure accurate volume of a solution ... |
Use this information to write a balanced equation to represent the reaction. Fe 56, Cl 35.5 . 3mks 9. A What is meant by atomic number? 1mk b An element P has a mass number of 35 and atomic number 17.Draw a diagram showing the Composition of electrons and the composition of the nucleus of its atom. 2mks 10. The table b... |
1mk 21. A State the Le Chatelier s principle 1mk b Carbon II oxide gas reacts with steam according to the equation. CO g H20 g H2 g CO 2 g What would be the effect of increasing pressure of the system at equilibrium .Explain 2mks 22. Given the following half cell equations; P2 aq 2e- P S E -2.37V Q2 aq 2e- S E -0.76V a... |
All working MUST be clearly shown where necessary 1. Study the figure below and answer the questions that follow a Write the formula of the organic compounds P and S 2mks b Name the types of reaction, the reagents and conditions for the reactions in the following steps 4mrks Reaction Reagent condition Step I Step II c ... |
An excess of copper carbonate is added to 50.0cm3 of 2M sulphuric VI acid in a beaker and the mixture warmed until no further reaction takes place. The warm mixture is then filtered and the filtrate evaporated until the volume reduced to 20.0cm3. The mixture is allowed to cool and the crystals formed dried and weighed.... |
1 mark vi State one use of sodium hydroxide. 1 mark b If a factory produces 1000 kg of sodium hydroxide in every 24 hours, calculate the required current per day. H 1.0, Na 23.0, O 16.0 2 marks 6. Study the following diagram below and use it to answer the questions that follow:- a Identify ions present in solid R 1mrk ... |
Study it and answer the questions that follow: S P Z T D Q C X J R a To which family do element P, Q and R belong? 1mrk b Write the electronic arrangements of stable ions of D and C 2mrks c Compare melting point of chlorides of Z and T 2mrks d Select the most reactive metallic element 1mrk e Give one use of element Q 1... |
Dilute nitric V acid supplied with a dropper 4. 0.5M Pb NO3 2 supplied with a dropper 5. 0.5g NaHCO3 supplied with a dropper 6. Acidified K2Cr2O7 supplied with a dropper 7. Acidified KMnO4 supplied with a dropper 8. Bromine water NB Each of the solutions in Bottle should be supplied with a dropper. Preparations Solutio... |
Allow the solution to cool while stirring with a thermometer. Record the temperature at which the crystals start to form in the table below Add a further 2cm3 of distilled water from the burette to the mixture Repeat procedure iv and v above and record the crystallization temperature. Complete the table below by adding... |
1 mark d Concentration of solution C in moles per litre 1 mark 2. A You are provided with: - Solid V, which could be iron III sulphate - 1 M nitric acid - 1 M sodium hydroxide - Source of heat - Distilled water - 0.1 M Lead II nitrate solution i From the reagents provided, describe three tests that may be carried out c... |
Na 23, O 16, H 1, S 32 3mks 6. Describe how you can extract oil from ground nuts? 3marks 7. Passing a small quantity of carbon iv oxide through calcium hydroxide, forms a white precipitate which dissolves when excess carbon IV oxide is bubbled through. A Name the white precipitate. Mk b Explain using a chemical equatio... |
1mk b Name process Y. 1mk www.freekcsepastpapers.comPage 296 c Write the molecular formula of the 5th member in which propene belong. 1mk 12. Study the reaction below and answer the questions that follow NH3 g H2O l NH4 aq OH- aq a Define the term acid 1mk b Identify an acid in the above reaction 1mk c Explain your ans... |
Study the diagram below and answer the questions that follow: a What do H1 and H2 represent? H1 1mkwww.freekcsepastpapers.comPage 297 H2 1mk b Write an expression to show the relationship between H1, H2 and H3. 1mk 18. Nitrogen and hydrogen react reversibly according to the equation:- N2 g 3H2 g 2NH3 g ; H -92kjmol-1 H... |
3.52g of Carbon IV Oxide and 1.40g of water are produced when a mass of a hydrocarbon is completely burnt in oxygen. Determine the empirical formula of the hydrocarbon; H 1 , C 12, O 16 3mks 24. A Hydrogen can reduce coppers Oxide but not aluminium oxide. Explain 1mk b When water reacts with potassium metal the hydroge... |
1 mark e The set-up below was used to investigate some of the properties of hydrogen gas. I State the observation made in the combustion tube. 1 mark ii Write down the equation leading to formation of liquid L. 1 mark iii What property of hydrogen is being investigated? 1 mark iv Why is potassium oxide not used to inve... |
1 mark b The scheme below represents some reactions of ethyne. Study it and answer the questions that follow. I Name compound P and draw its structural formula. 2 marks ii Identify the reagents used in: I Process R 1 mark II Step I 1 mark iii Draw the repeating unit in polymer T. 1 mark iv Name polymer T ... 1 mark v G... |
K L M N P Q R S T V W a Name the family to which element P belongs. 1mark b Which two elements will form carbonates that do not decompose on heating. 1 mark c With a reason, identify an element in period three with the largest atomic radius. 2marks d Write the formula of the compound formed between L and M 1 mark e Sta... |
Molar volume at s.t.p 22.4dm3, zn 65 2 marks e On the same axis, draw a sketch of the graph that would be obtained if the zinc granules are reacted with 1.0M hydrochloric acid. 1 mark www.freekcsepastpapers.comPage 303 BOKAKE JOINT EXAMINATIONS, 2023 Kenya Certificate of Secondary Education 233 3 CHEMISTRY Practical 3 ... |
4mks Beaker 1 2 3 4 Volume of acid cm3 10 8 6 4 Volume of water cm3 0 2 4 6 Time second a Plot a graph of volume of acid cm3 against time sec in the graph provided. 3mks b From the graph determine; i Time taken for magnesium to disappear completely at 5cm3 1mk ii Volume of the acid in which magnesium takes 100 seconds ... |
1713.17METALWORK 445 3.17.1 Metalwork Paper 1 445 1 For More Free KCSE Past papers Visit www.freekcsepastpapers.com172For More Free KCSE Past papers Visit www.freekcsepastpapers.com173For More Free KCSE Past papers Visit www.freekcsepastpapers.com174For More Free KCSE Past papers Visit www.freekcsepastpapers.com. |
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1-The method of switching the starting winding is by a centrifugal switch. 1 This allows the starting winding to be switched off before the motor reaches its normal speed. 1-Once the motor reaches its normal speed, it runs with only one winding energized. 14 marks b i Load current I2 VP 1 24024000100A cm 21 ii For an i... |
14 marks b 218 parts 21 4 marksLow high current circuit 2 marksTOTAL 6 marksFor More Free KCSE Past papers Visit www.freekcsepastpapers.com587- When the remote switch is closed. Current flows through the coil making it an electromagnet.1-The electromagnet attracts the armature which closes the circuit.1-The load in the... |
Www.freekcsepastpapers.comGEOGRAPHY PAPER 1 2 222 IMENTI SOUTH 312 1 GEOGRAPHY PAPER 1 SECTION A 25 marks Answer all the questions in this section 1. A Differentiate between physical and human environment. 2 marks b State three reasons why it s important to study Geography. 3 marks 2. A Define a meteor. 2 marks b State... |
3 marks b i State two factors that contribute to soil leaching. 2 marks ii List five characteristics of desert soils. 5 marks iii State three importance of soil texture. 3 marks c Students from your school carried out field study of soils found in Nyika Plateau. I State three methods they are likely to use to collect d... |
3 marks c The following diagram represents a feature found in a Karst Scenery. Use it to answer the questions that follow. I Name the parts labelled X and Z. 2 marks ii Describe the formation of the feature marked Y 3 marks d State the significance of a Karst landscape. 5 marks IMENTI SOUTH 312 2 GEOGRAPHY PAPER 2 SECT... |
Year Area Open woodland Indigenous Tree farm lands Private plantation forests 2006 6800 4700 2400 800 2007 7200 3800 2000 400 2008 6400 1400 1900 500 2009 5400 4600 2000 700 Calculate the percentage decrease in the area under open woodland forest in Kenya. 3 marks b i Draw a compound bar graph to represent the data abo... |
4 marks d What three problems could the students have experienced during the field study? 3 marks 8.a i Name two areas within western region sugar Belt where large scale sugarcane cultivation ispracticed. 2 marks ii Explain three human requirements that favour sugarcane growing in Kenya. 3 marks b i Name two diseases w... |
2mks Physical environment refers to features that are natural although their presence have influenced human activities while human environment comprises of activities of people on the earths surface. 2mks b State three reasons why it is important to study Geography. 3mks It promotes awareness on sustainable use of reso... |
State four effects of rotation of the earth 4marks 3. The diagram below represents zones of natural vegetation on a mountain. Use it to answer questions that follow a Identify the vegetation zones marked X and Y. 2marks b State four characteristics of tropical rainforest vegetation. 4marks 4. A Identify two erosional p... |
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