- The PH of a soil sample was found to be 5.7. An agricultural officer recommended addition of lime.
(a) State two functions of the lime.
(b)...(Solved)
The PH of a soil sample was found to be 5.7. An agricultural officer recommended addition of lime. State two functions of the lime.
Date posted: March 27, 2019. Answers (1)
- An element X has a relative atomic mass of 88. When a current of 0.5 ampere was passed through a fused chloride of X for...(Solved)
An element X has a relative atomic mass of 88. When a current of 0.5 ampere was passed through a fused chloride of X for 32 minutes 10 seconds, 0.44g of X was deposited.
(i) Determine the charge of element X [1 Faraday = 96500C]
(ii) Write the formula of hydroxide of X
Date posted: March 27, 2019. Answers (1)
- A form two student in an attempt to prevent rusting put copper and zinc in contact with iron as shown below.(Solved)
A form two student in an attempt to prevent rusting put copper and zinc in contact with iron as shown below.
(i) State what would happen in set up X and Y after one week.
(ii) Explain your answer in diagram Y.
Date posted: March 27, 2019. Answers (1)
- Study the information in the table and answer the questions below.(Solved)
Study the information in the table and answer the questions below.
Describe how a solid sample of substance V could be obtained from a solid mixture of V and W.
Date posted: March 27, 2019. Answers (1)
- Volume of liquids can be measured using a pipette; measuring cylinder or burette. Explain which one would be best for measuring 29.1cm3 of liquid.(Solved)
Volume of liquids can be measured using a pipette; measuring cylinder or burette. Explain which one would be best for measuring 29.1cm3 of liquid.
Date posted: March 27, 2019. Answers (1)
- 0.318g of an oxide of metal M was completely reduced by hydrogen gas to 0.254g of metal. Calculate empirical formula of the metal oxide. (M...(Solved)
0.318g of an oxide of metal M was completely reduced by hydrogen gas to 0.254g of metal. Calculate empirical formula of the metal oxide. (M = 63.5, O = 16)
Date posted: March 27, 2019. Answers (1)
- The volume of a gas at 300C and 780mmHg is 400cm3. What will be its volume at 500C at 600mmHg.(Solved)
The volume of a gas at 300C and 780mmHg is 400cm3. What will be its volume at 500C at 600mmHg.
Date posted: March 27, 2019. Answers (1)
- 15g of sodium chloride was dissolved in 120cm3 of distilled water. Calculate the concentration of the resulting solution in moles per litre. (Na = 23,...(Solved)
15g of sodium chloride was dissolved in 120cm3 of distilled water. Calculate the concentration of the resulting solution in moles per litre. (Na = 23, Cl = 35.5)
Date posted: March 27, 2019. Answers (1)
- The table below gives the rate of decay of a radioactive element G.(Solved)
The table below gives the rate of decay of a radioactive element G.
Calculate the half-life of the radioactive element G.
Date posted: March 27, 2019. Answers (1)
- Study the diagram below and answer the questions that follow.(Solved)
Study the diagram below and answer the questions that follow.
(i) What is the purpose of passing tap water through the air aspirator?
(ii) State and explain the observation that would be made in tube M after sometime.
Date posted: March 27, 2019. Answers (1)
- The diagram below shows a burning jiko. Study it and answer the questions that follow.(Solved)
The diagram below shows a burning jiko. Study it and answer the questions that follow.
(a) Write the equation for the reaction taking place in region A.
(b) Name the gas produced at region B.
(c) State ONE use of the gas named in (b) above.
Date posted: March 27, 2019. Answers (1)
- The table below gives some elements in the periodic table. Use it to answer the questions that follow. The letters do not represent the actual...(Solved)
The table below gives some elements in the periodic table. Use it to answer the questions that follow. The letters do not represent the actual symbols of the elements.
(a) A metallic element which forms ions with the smallest ionic radius? Explain
(b) A non metallic element with the largest atomic size? Explain.
Date posted: March 27, 2019. Answers (1)
- Study the following equilibrium equation.(Solved)
Study the following equilibrium equation.
Suggest two ways of increasing the yield of X2Y.
Date posted: March 27, 2019. Answers (1)
- The curves below represent the volume of carbon (IV) oxide gas evolved once 2M(concentrated) hydrochloric acid was reacted with 100g of powdered calcium carbonate and...(Solved)
The curves below represent the volume of carbon (IV) oxide gas evolved once 2M(concentrated) hydrochloric acid was reacted with 100g of powdered calcium carbonate and also when 1M concentrated hydrochloric acid was reacted with the same quantity of carbonate.
(i) Which of the two curves represents the reaction of 2M concentrated HCl with powdered calcium carbonate. Give a reason.
(ii) Why do the two curves flatten at the same level of production of CO2.
Date posted: March 27, 2019. Answers (1)
- The scheme below shows some reactions starting with ethyne. Study it and answer the questions that follow.(Solved)
The scheme below shows some reactions starting with ethyne. Study it and answer the questions that follow.
(a) Name substance X and N
(b) Name reagent M
(c) Ethene undergoes polymerization to form a polymer. Give an equation for the reaction and name the product.
(i) Equation;
(ii) Name:
Date posted: March 27, 2019. Answers (1)
- Calculate the volume of oxygen produced when 10g of silver nitrate was completely decomposed by heating at (s.t.p) (Ag =108, N = 14, O =...(Solved)
Calculate the volume of oxygen produced when 10g of silver nitrate was completely decomposed by heating at (s.t.p) (Ag =108, N = 14, O = 16) Molar gas volume at s.t.p = 22.4dm3)
Date posted: March 27, 2019. Answers (1)
- 100cm3 of methane gas diffused through a porous partition in 40 seconds. How long would it take 90cm3 of ozone gas to diffuse through the...(Solved)
100cm3 of methane gas diffused through a porous partition in 40 seconds. How long would it take 90cm3 of ozone gas to diffuse through the same partition? (C = 12, H = 1, O = 16)
Date posted: March 27, 2019. Answers (1)
- The diagram below shows part of Solvay Process.(Solved)
The diagram below shows part of Solvay Process.
(a) Name solid P
(b) State the process taking place in chamber N.
(c) State two uses of calcium chloride which is a by-product in this process.
Date posted: March 27, 2019. Answers (1)
- The diagram below shows a set up which was used by student to investigate effect of electricity on solid Molten Lead (II) Bromide. Study it...(Solved)
The diagram below shows a set up which was used by student to investigate effect of electricity on solid Molten Lead (II) Bromide. Study it and answer the questions that follow.
(a) (i) State and explain the observation at the anode when the switch is switched on.
(ii) What precaution should be taken when carrying out this experiment?
(iii) Write the equation of the reaction taking place at the Anode.
(iv) Why are graphite electrodes used in the experiment?
(v) On the diagram, indicate the direction of flow of electrons.
(vi) The students noted that the bulb only produced light after the Lead (II) Bromide had melted. Explain this observation.
(b) State the difference in conduction of electric current between Molten Lead (II) Bromide and Lead Metal.
(c) Explain why it is not advisable to store Copper (II) Sulphate solution in a can made of Zinc metal.
(d) State two applications of electrolysis.
Date posted: March 27, 2019. Answers (1)
- The flow chart below shows the Haber process in the large scale manufacture of Ammonia gas. Use it to answer the questions that follow.(Solved)
The flow chart below shows the Haber process in the large scale manufacture of Ammonia gas. Use it to answer the questions that follow.
Describe how nitrogen is obtained from air on a large scale.
(a) (i) Name one source of hydrogen gas used as a raw material in the above process.
(ii) Name chamber A.
(iii) Write an equation for the reaction taking place in the catalytic chamber.
(iv) In the Haber process optimum temperature of 5000C and 200 atmospheres of pressure are used to get optimum yield of
Ammonia. Why can’t lower temperatures and higher pressure be used?
(b) Give two reasons why finely divided iron is the commonly used catalyst.
(c) State and explain the observation made when dry ammonia gas is passed over heated copper (II) Oxide
in a combustion tube.
(d) Give two uses of ammonia gas.
Date posted: March 27, 2019. Answers (1)