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maurice.mutuku answered the question on September 19, 2019 at 07:17
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The diagram below shows the set-up that can be used to prepare and collect oxygen gas. Study it and answer the questions that follow.
(Solved)
The diagram below shows the set-up that can be used to prepare and collect oxygen gas. Study it and answer the questions that follow.

Identify two mistakes from the diagram which must be corrected for one to collect dry oxygen gas.
Date posted:
September 19, 2019
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Answers (1)
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State the conditions under which ammonia gives the following products when heated
(i) Nitrogen and hydrogen.
(ii) Nitrogen and water.
(iii) Nitrogen (II) oxide and water.
(Solved)
State the conditions under which ammonia gives the following products when heated
(i) Nitrogen and hydrogen.
(ii) Nitrogen and water.
(iii) Nitrogen (II) oxide and water.
Date posted:
September 19, 2019
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Answers (1)
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The following diagram was used to study a property of hydrogen gas. Study it and answer the questions that follow.
(Solved)
The following diagram was used to study a property of hydrogen gas. Study it and answer the questions that follow.

a) Name the missing condition in the above set up.
b) Explain why the combustion tube is clamped in a slanting position.
c) Before lighting the gas at the end of delivery tube, hydrogen must be let to pass through until all the air is driven out. Explain.
d) State three observations that occur in the combustion tube.
e) Why was hydrogen gas burnt at point Z.
f) Why should the supply of hydrogen gas be continued while the apparatus cool.
g) What would be observed if the experiment was repeated using lead (II) oxide.
h) Other than the property investigated above, name two other chemical properties of hydrogen gas.
Date posted:
September 19, 2019
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Answers (1)
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Calculate the mass of sodium carbonate contained in 200cm3 of 0.02M sodium carbonate solution.
(Solved)
Calculate the mass of sodium carbonate contained in 200cm3 of 0.02M sodium carbonate solution.
Date posted:
September 19, 2019
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Answers (1)
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A sample of 10cm3 of hydrogen sulphide was burned in 40cm3 of oxygen. Calculate the volume and composition of residual gas (assume all volumes are...
(Solved)
A sample of 10cm3 of hydrogen sulphide was burned in 40cm3 of oxygen. Calculate the volume and composition of residual gas (assume all volumes are measured at s.t.p)
Date posted:
September 19, 2019
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Answers (1)
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The diagram below represents a set up that was used for electrolysis of aqueous copper (II) nitrate.
(Solved)
The diagram below represents a set up that was used for electrolysis of aqueous copper (II) nitrate.

A gas that relights a glowing splint was produced at electrode A.
i) Which electrode is the cathode ? Explain.
ii) State another suitable method for collecting gas X.
iii) Write ionic equations to show reactions that take place at the :
Anode
Cathode
iv) Explain how the identity of the product at the cathode of this electrolysis can be confirmed.
v) Calculate the mass of copper deposited if a constant current of 5 A was passed for 3 hours. (Cu = 63.5, IF = 965000)
Date posted:
September 18, 2019
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Answers (1)
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Excess concentrated sulphuric VI acid was mixed with pieces of dry wood as shown.
(Solved)
Excess concentrated sulphuric VI acid was mixed with pieces of dry wood as shown.

a) State the observation made in the tube.
b) When the reaction was complete, the mixture was heated gently, then strongly and set up adjusted as shown below.

State and explain the observation made on acidified potassium chromate VI solution.
Date posted:
September 18, 2019
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Answers (1)
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The table below shows properties of some chlorides. Study it and answer the questions that follow.
(Solved)
The table below shows properties of some chlorides. Study it and answer the questions that follow.

a) Explain the high melting and boiling points of sodium chloride.
b) Write an equation for the reaction between PC15 and water.
c) Draw the dot (•) and cross (x) diagram to show bonding in NaCl.
Date posted:
September 18, 2019
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Answers (1)
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The labels of two reagent bottles contained the following safety symbols.
(Solved)
The labels of two reagent bottles contained the following safety symbols.

a) What do the symbols mean ? Explain.
b) Which of the reagent is more harmful ?
Date posted:
September 18, 2019
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Answers (1)
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What volume of oxygen gas at r.t.p will be liberated at the anode when a current of 3 amperes is passed through magnesium sulphate solution...
(Solved)
What volume of oxygen gas at r.t.p will be liberated at the anode when a current of 3 amperes is passed through magnesium sulphate solution for 45 minutes and 30 seconds. (Molar gas volume at r.t.p = 24000cm3, Faraday constant = 96500
Coulombs)
Date posted:
September 18, 2019
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Answers (1)
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When bismuth III Chloride is added to water, a reaction occurs and a white precipitate forms as shown below.
BiCI3(aq) + H20(l) BiOCl(s) + 2HCl(aq)
What would...
(Solved)
When bismuth III Chloride is added to water, a reaction occurs and a white precipitate forms as shown below.
BiCI3(aq) + H20(l) BiOCl(s) + 2HCl(aq)
What would be the effect on the amount of the precipitate formed if sodium hydroxide solution is added to the equilibrium mixture ? Explain your answer.
Date posted:
September 18, 2019
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Answers (1)
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Explain why iron nails rust faster in sodium chloride solution than in tap water.
(Solved)
Explain why iron nails rust faster in sodium chloride solution than in tap water.
Date posted:
September 18, 2019
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Answers (1)
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Given the following reagents; solid sodium carbonate, solid lead (II) nitrate, water. Describe how a sample of lead (II) carbonate can be prepared in the...
(Solved)
Given the following reagents; solid sodium carbonate, solid lead (II) nitrate, water. Describe how a sample of lead (II) carbonate can be prepared in the laboratory.
Date posted:
September 18, 2019
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Answers (1)
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Two elements X and Y are represented as shown below
(Solved)
Two elements X and Y are represented as shown below
17X and 20Y
i) Write the formula of the compound formed when X and Y react.
ii) State the family name to which element X belongs.
iii) Element Y has a mass number of 40, how many neutrons are present in its nucleus?
Date posted:
September 18, 2019
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Answers (1)
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Ethanol has a molar heat of combustion of -1360kJmol-1. Calculate the heating value of ethanol. (C=12,H=1,O=16
(Solved)
Ethanol has a molar heat of combustion of -1360kJmol-1. Calculate the heating value of ethanol. (C=12,H=1,O=16
Date posted:
September 18, 2019
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Answers (1)
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A volume of 10cm3 of ethene gas (C2H4) was exploded with 50cm3 of oxygen.
(i) Write the equation of the reaction for the combustion of ethene.
(ii)...
(Solved)
A volume of 10cm3 of ethene gas (C2H4) was exploded with 50cm3 of oxygen.
(i) Write the equation of the reaction for the combustion of ethene.
(ii) Calculate the volume of gaseous mixture.
Date posted:
September 18, 2019
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Answers (1)
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During the electrolysis, a current of 2 amperes was passed through the copper (II) sulphate solution for 4 hours. Calculate the volume of the gas...
(Solved)
During the electrolysis, a current of 2 amperes was passed through the copper (II) sulphate solution for 4 hours. Calculate the volume of the gas produced at the anode. (1 F= 96500 C, MGV = 24000cm3).
Date posted:
September 18, 2019
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Answers (1)
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The solubility of iron (II) sulphate at 22oC is 15.65g/100g of water. Calculate the mass of iron (II) sulphate crystals in 90g of saturated iron...
(Solved)
The solubility of iron (II) sulphate at 22oC is 15.65g/100g of water. Calculate the mass of iron (II) sulphate crystals in 90g of saturated iron (II) sulphate solution.
Date posted:
September 18, 2019
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Answers (1)
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Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.
(Solved)
Pentanoic acid reacts with butan – 1 – 0l to form an organic compound.
(i) Write an equation to show the above reaction.
(ii) What is the name given to the above type of reaction?
(iii) A few drops of a certain catalyst must be added to the mixture to increase the rate of the reaction.
(a) Name the catalyst.
(b) Explain the role of the catalyst in the above reaction.
Date posted:
September 18, 2019
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Answers (1)
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Draw the structures of the following compounds.
i) Ethylbutanoate
ii) 3-ethyl – 3 – methyl hexane
(Solved)
Draw the structures of the following compounds.
i) Ethylbutanoate
ii) 3-ethyl – 3 – methyl hexane
Date posted:
September 17, 2019
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Answers (1)