(i) - P
- It reacts with the carbonate faster and the reaction ends earlier.
(ii) The same quantities of reactants have been used hence total volume of gas evolved is the same.
sharon kalunda answered the question on March 27, 2019 at 11:45
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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
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Answers (1)
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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
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Answers (1)
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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
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Answers (1)
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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
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Answers (1)
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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
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Answers (1)
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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
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Answers (1)
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Study the flow chart below and answer the questions that follow.
(Solved)
Study the flow chart below and answer the questions that follow.

(i) Name the process taking place in step (I).
(ii) Describe chemical test that can be carried out to show the identity of organic compound A.
(iii) Give the name of the following:
I. A:
II. B:
(iv) Give the structural formulae of substance C.
(v) Name the type of reaction that occurs in:
I. Step IV
II. Step VI:
(vi) Give the reagent and the condition necessary for step VI.
Reagent:
Condition:
(b) Give the systematic names of the following compounds:
I. CH2CHCHCH2CH3
II. CH C C H3
Date posted:
March 27, 2019
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Answers (1)
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During Olympics, urine sample of five short distance runners were taken and tested for the presence of two illegal steroids by paper chromatography. Methanol was...
(Solved)
During Olympics, urine sample of five short distance runners were taken and tested for the presence of two illegal steroids by paper chromatography. Methanol was used as the solvent. A chromatogram from the test appeared as shown below. Study the chromatogram and answer the questions that follow.

(a) Which of the two steroids is most likely to be more soluble in methanol? Give a reason.
(b) Identify the athletes that tested positive for the illegal steroids.
Date posted:
March 27, 2019
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Answers (1)
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Some salts may be classified as double salts or basic salts. Trona with the formula Na2CO3.NaHCO3 is an example of a double salt. An example...
(Solved)
Some salts may be classified as double salts or basic salts. Trona with the formula Na2CO3.NaHCO3 is an example of a double salt. An example of a basic salt is basic magnesium carbonate with formula MgCO3.Mg(OH)2.
(a) What is meant by a double salt?
(b) Write equations of reactions that occur when dilute hydrochloric acid is reacted with:
(i) Trona
(ii) Basic magnesium carbonate.
Date posted:
March 27, 2019
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Answers (1)
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A gaseous compound consists of 86% carbon and 14% hydrogen by mass. At s.t.p. 3.2dm3 of the compound had a mass of 6g. Calculate its...
(Solved)
A gaseous compound consists of 86% carbon and 14% hydrogen by mass. At s.t.p. 3.2dm3 of the compound had a mass of 6g. Calculate its molecular formula.(1 mole of a gas at s.t.p. = 22.4dm3)
Date posted:
March 27, 2019
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Answers (1)
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An experiment was set up using chlorine water as shown below.
(Solved)
An experiment was set up using chlorine water as shown below.

(i) Identify gas X.
(ii) Write an equation for the production of gas X.
Date posted:
March 27, 2019
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Answers (1)
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The set-up below shows the catalytic oxidation of ammonia in the laboratory.
(Solved)
The set-up below shows the catalytic oxidation of ammonia in the laboratory.

(a) Identify the brown fumes observed at the mouth of the conical flask.
(b) Write down the equations of the reactions representing
(i) Catalytic oxidation of ammonia
(ii) The formation of the brown fumes.
Date posted:
March 27, 2019
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Answers (1)
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State three reasons why air is considered to be a mixture but not a compound.
(Solved)
State three reasons why air is considered to be a mixture but not a compound.
Date posted:
March 27, 2019
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Answers (1)
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Below is a set-up of apparatus used to prepare hydrogen gas in the laboratory. Study it and answer the questions that follow.
(Solved)
Below is a set-up of apparatus used to prepare hydrogen gas in the laboratory. Study it and answer the questions that follow.

(a) Write a chemical equation for the two reactions taking place in he above set-up.
(b) State the chemical test for hydrogen gas.
Date posted:
March 27, 2019
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Answers (1)
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In an experiment to study properties of carbon, a small amount of charcoal is placed in a boiling tube. 5.0cm3 of concentrated nitric acid is...
(Solved)
In an experiment to study properties of carbon, a small amount of charcoal is placed in a boiling tube. 5.0cm3 of concentrated nitric acid is added. The mixture is then heated.
(a) What observations are made?
(b) Write an equation for the reaction that took place in the boiling tube.
(c) What property of carbon is shown in this reaction?
Date posted:
March 27, 2019
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Answers (1)
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The graph below shows the amount of calcium carbonate and calcium chloride varying with time in the reaction.
(Solved)
The graph below shows the amount of calcium carbonate and calcium chloride varying with time in the reaction.

(a) Which curve shows the amount of calcium chloride varying with time?
(b) Explain why the two curves become horizontal after a given period of time.
Date posted:
March 27, 2019
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Answers (1)
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The table below gives the solubility of potassium bromide and potassium sulphate at 00C and 400C.
(Solved)
The table below gives the solubility of potassium bromide and potassium sulphate at 00C and 400C.

When an aqueous mixture containing 60g of potassium bromide and 7g potassium sulphate in 100g of water at 800C was cooled to 00C, some crystals were formed.
(a) Identify the crystals.
(b) Determine the mass of the crystals.
Date posted:
March 27, 2019
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Answers (1)
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The structure below represents two cleansing agents A and B. Which cleansing agent would be suitable for washing in water containing calcium chloride? Give a...
(Solved)
The structure below represents two cleansing agents A and B. Which cleansing agent would be suitable for washing in water containing calcium chloride? Give a reason.

Date posted:
March 26, 2019
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Answers (1)
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The products of a burning candle were passed through a tube containing calcium oxide as shown in the diagram below.
(Solved)
The products of a burning candle were passed through a tube containing calcium oxide as shown in the diagram below.

(a) Write two chemical equations for the reactions that took place in tube P.
(b) Name two gases that came out through tube R.
Date posted:
March 26, 2019
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Answers (1)
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Excess Carbon (II) Oxide was passed over a heated sample of an oxide of iron as shown in the diagram below. Study the diagram and...
(Solved)
Excess Carbon (II) Oxide was passed over a heated sample of an oxide of iron as shown in the diagram below. Study the diagram and the data and use it to answer the questions that follow

Mass of empty dish =6.72g
Mass of empty dish + oxide of iron =9.04g
Mass of empty dish + residue=8.40g
(a) Determine the formula of the oxide of iron given that the relative formula mass of oxide of Iron = 232, Fe = 56.0, O=16.0
(b) Write an equation for the reaction which took place in the dish
Date posted:
March 26, 2019
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Answers (1)