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When X cm3 of a solution of 0.5m magnesium carbonate was 8.4g.
a) Write the ionic equation for the reaction that took place
b) Calculate the value...
(Solved)
When X cm3 of a solution of 0.5m magnesium carbonate was 8.4g.
a) Write the ionic equation for the reaction that took place
b) Calculate the value of X. (C = 12.0, Mg 24.0; 016.0
Date posted:
June 24, 2019
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Answers (1)
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Draw the structure of the smallest repeating unit of a polyvinyl chloride
(Solved)
Draw the structure of the smallest repeating unit of a polyvinyl chloride
Date posted:
June 24, 2019
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Answers (1)
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Draw the structural formula of the third member of the homologous series of ethyne.
(Solved)
Draw the structural formula of the third member of the homologous series of ethyne.
Date posted:
June 24, 2019
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Answers (1)
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State how burning can be used to distinguish between ethane and ethyne.
Explain your answer.
(Solved)
State how burning can be used to distinguish between ethane and ethyne.
Explain your answer.
Date posted:
June 24, 2019
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Answers (1)
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1.2 litres of hydrogen gas produced at room temperature and pressure when
3.27g of zinc was used. Determine the relative atomic mass of zinc.(Molar gas
volume is...
(Solved)
1.2 litres of hydrogen gas produced at room temperature and pressure when
3.27g of zinc was used. Determine the relative atomic mass of zinc.(Molar gas
volume is 24 litres)
Date posted:
June 24, 2019
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Answers (1)
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The set – up below was used to (electrolyse roller lead (II) iodide. i) State the observation that was made at the anode during the electrolysis.Give...
(Solved)
The set – up below was used to (electrolyse roller lead (II) iodide.

i) State the observation that was made at the anode during the electrolysis.
Give a reason for your answer.(2mk)
ii) A current of 0.5 A was passed for two hours. Calculate the mass of lead
that was deposited (pb = 1F = 9,500C)
Date posted:
June 24, 2019
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Answers (1)
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State the observation made when excess pentane is reacted with bromine gas
(Solved)
State the observation made when excess pentane is reacted with bromine gas
Date posted:
June 24, 2019
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Answers (1)
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When excess dilute hydrochloric acid was added to sodium , 960cm3 of sulphur (IV)
oxide gas was produced. Calculate the mass of sodium sulphite that was...
(Solved)
When excess dilute hydrochloric acid was added to sodium , 960cm3 of sulphur (IV)
oxide gas was produced. Calculate the mass of sodium sulphite that was used. (molar
mass of sodium = 126 g and molar gas volume= 24000cm3
Date posted:
June 24, 2019
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Answers (1)
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Name the product formed when methanol reacts with methanoic acid
(Solved)
Name the product formed when methanol reacts with methanoic acid
Date posted:
June 24, 2019
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Answers (1)
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In the preparation of a bleaching agent (Sodium hypochlorite), Excess chlorine gas was
bubbled into 15 litres of cold 2 m sodium hydroxide
(i) Write an equation...
(Solved)
In the preparation of a bleaching agent (Sodium hypochlorite), Excess chlorine gas was
bubbled into 15 litres of cold 2 m sodium hydroxide
(i) Write an equation for the reaction between chlorine gas and cold dilute sodium
Hydroxide
(ii) Calculate the:
Number of moles of sodium hydroxide used
Mass in kilograms of the sodium hypochlorite produced = 1. 1175
Date posted:
June 24, 2019
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Answers (1)
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Name one suitable drying agent for ammonia gas.
(Solved)
Name one suitable drying agent for ammonia gas.
Date posted:
June 24, 2019
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Answers (1)
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When excess lead nitrate solution was added to a solution containing sodium chloride,
the precipitate formed was found to weigh 5.56 g. Determine the amount of...
(Solved)
When excess lead nitrate solution was added to a solution containing sodium chloride,
the precipitate formed was found to weigh 5.56 g. Determine the amount of sodium
chloride in the solution ( Pb = 207, Cl = 35.5 Na = 23)
PbXO3(aq) + 2NaCl (aq) → PbCI2 + NaNO3 (aq) (l)
Date posted:
June 24, 2019
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Answers (1)
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When carbon dioxide gas was passed through aqueous calcium hydroxide a white
suspension was formed
(a) Write an equation for the reaction that took place
(b) State and...
(Solved)
When carbon dioxide gas was passed through aqueous calcium hydroxide a white
suspension was formed
(a) Write an equation for the reaction that took place
(b) State and explain the changes that would occur when carbon dioxide gas is bubbled
through the white suspension
Date posted:
June 24, 2019
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Answers (1)
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In an experiment to study the rate for reaction between duralumin (an alloy of aluminium,
magnesium and copper) and hydrochloric acid, 0.5g of the alloy were...
(Solved)
In an experiment to study the rate for reaction between duralumin (an alloy of aluminium,
magnesium and copper) and hydrochloric acid, 0.5g of the alloy were reacted with excess
4M hydrochloric acid. The data in the table below was recoded.
Use it to answer the questions that follow.

a) i) On the grid provided, plot a graph of total volume of gas produced (vertical axis)
again time.
ii) From the graph, determine the volume of gas produced at the end of 2 ½ minutes.
b) Determine the rate of reaction between the 3rd and 4th minute.
c) Give a reason why some solid remained at the end of the experiment
d) Given that 2.5cm3 of the total volume of the gas was from the reaction between
magnesium and aqueous hydrochloric acid, calculate the percentage mass of aluminium
present in 0.5g of the alloy.
(Al = 27.0 and Molar gas volume = 24,000cm3 at 298k)
e) State two properties of duralumin that make it more suitable than aluminium in aeroplane
construction.
Date posted:
June 24, 2019
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Answers (1)
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A weighed sample of crystalline sodium carbonate (Na2CO3. H2O) was heated in a
crucible until there was no further change in mass.
Calculate the number of moles...
(Solved)
A weighed sample of crystalline sodium carbonate (Na2CO3. H2O) was heated in a
crucible until there was no further change in mass.
Calculate the number of moles (n) of the water of crystallization
Date posted:
June 24, 2019
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Answers (1)
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(i) In the space provided sketch a labeled diagram to show how hydrogen
chloride gas can be prepared and collected in the laboratory using sodium
Chloride and...
(Solved)
(i) In the space provided sketch a labeled diagram to show how hydrogen
chloride gas can be prepared and collected in the laboratory using sodium
Chloride and concentrated sulphuric acid ( the gas need not be dry)
(ii) Write an equation for the reaction that takes place
(iii) Name one drying agent for hydrogen chloride
(vi) State and explain the observation that would be made when hydrogen
chloride gas is bubbled through a solution of lead (II) nitrate
(v) Concentrated hydrochloric acid is used for removing oxide from metal surfaces (
picking). Explain why concentration nitric acid cannot be used for the purpose.
Date posted:
June 24, 2019
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Answers (1)
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A given volume of ozone, (O3) diffused from a certain apparatus in 96 seconds.
Calculate the time taken by an equal volume of carbon dioxide (CO2)...
(Solved)
A given volume of ozone, (O3) diffused from a certain apparatus in 96 seconds.
Calculate the time taken by an equal volume of carbon dioxide (CO2) to diffuse under
the same conditions (O = 16.0, C = 12.0)
Date posted:
June 24, 2019
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Answers (1)
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A hydrocarbon P was found to decolourise bromine water. On complete combustion of 2
moles of P, 6 moles of carbon dioxide and 6 moles of...
(Solved)
A hydrocarbon P was found to decolourise bromine water. On complete combustion of 2
moles of P, 6 moles of carbon dioxide and 6 moles of water were formed
(a) Write the structural formula of P
(b) Give the name of P
(c) Name one industrial source of P
Date posted:
June 24, 2019
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Answers (1)
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An ore is suspected to contain mainly iron. Describe a method that
can be used to confirm the presence of iron in the ore
(Solved)
An ore is suspected to contain mainly iron. Describe a method that
can be used to confirm the presence of iron in the ore
Date posted:
June 22, 2019
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Answers (1)
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A sealed glass tube containing air at s.t.p was immersed in water at 1000c. Assuming
that there was no increase in the volume of the glass...
(Solved)
A sealed glass tube containing air at s.t.p was immersed in water at 1000c. Assuming
that there was no increase in the volume of the glass tube due to the expansion of the
glass, calculate the pressure of the inside tube. (standard pressure = 760mmHg,)
Date posted:
June 22, 2019
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Answers (1)