CHEMISTRY TOPICAL QUESTIONS AND ANSWERS

The following set – up was made in an experiment by a group of form four students. The readings of the balance before and after experiment were indicated in the diagram below.

14/10/2021

The following set – up was made in an experiment by a group of form four students. The readings of the balance before and after experiment were indicated in the diagram below. Given that the initial temperature of water was 26.7 degrees centigrade respectively. The specific heat capacity of water is 4200Jkg-1k-1

Determine:

a) Temperature change that occurred (1mk)

b) Amount of ethanol used (1mk)

10.5 – 1.0 = 9.5g

c) Moles of ethanol used (2mks)

d) Amount of heat gained by water (2mks)

e) Molar enthalpy of combustion of ethanol (2mks)

f) Use the following thermochemical processes to answer the questions that follow;

i) Draw an energy level diagram representing the formation and combustion processes of propane, carbon and hydrogen (2mks)

ii) Hence or otherwise, determine the heat of formation of propane (2mks)

Comments

Use the flow chart below to answer the questions that follow

13/10/2021

Comments

Use the flow chart below to answer the questions that follow

Use the flow chart above to answer the questions that follow

a) Name the following;

i) Gas L (1mk)

Gas L – Carbon (IV) Oxide

ii) Gas H (1mk)

Gas H – Hydrogen

iii) K (1mk)

K – Propane

b) Name the processes involved in the following steps

i) Step I (1mk)

Step I : Hydrogen

ii) Step II (1mk)

Step II – Neutralization

iii) Step III (1mk)

Step III – Substitution

c) Draw the structure of compound E (1mk)

d) Write a chemical equation for the complete combustion of substance F (1mk)

e) Name the condition and reagents in step III

i) Condition (1mk)

U.V light

ii) Reagent (1mk)

Chlorine

f) Calculate the mass of salt Q that would be formed by using 21.9kg of G when it reacts with excess sodium hydroxide (2mks)
(C = 120, H = 1.0, Na = 23.0, O = 16.0)

g) i) Draw the structure of polymer D (1mk)

ii) State one use of the above polymer (1mk)

Mouldings
Plastic ropes / Synthetic fibres
Use in films

Comments

A volume of 80cm3 of a mixture of propane (C3H8) and oxygen were ignited in an experiment. The products were cooled and passed through an aqueous sodium hydroxide. The final volume was reduced by 30cm3

11/10/2021

Comments

A volume of 80cm³ of a mixture of propane (C₃H₈) and oxygen were ignited in an experiment. The products were cooled and passed through an aqueous sodium hydroxide. The final volume was reduced by 30cm³

a) Write the equation for the combustion of propane (1mk)

b) Determine the volume of;

i) The component of the original mixture (2mks)

ii) Residual oxygen (1mk)

Comments

The following set – up was made in an experiment by a group of form four students. The readings of the balance before and after experiment were indicated in the diagram below.

Determine:

a) Temperature change that occurred (1mk)

b) Amount of ethanol used (1mk)

c) Moles of ethanol used (2mks)

d) Amount of heat gained by water (2mks)

e) Molar enthalpy of combustion of ethanol (2mks)

f) Use the following thermochemical processes to answer the questions that follow;

i) Draw an energy level diagram representing the formation and combustion processes of propane, carbon and hydrogen (2mks)

ii) Hence or otherwise, determine the heat of formation of propane (2mks)

Use the flow chart below to answer the questions that follow

a) Name the following;

i) Gas L (1mk)

ii) Gas H (1mk)

iii) K (1mk)

b) Name the processes involved in the following steps

i) Step I (1mk)

ii) Step II (1mk)

iii) Step III (1mk)

c) Draw the structure of compound E (1mk)

d) Write a chemical equation for the complete combustion of substance F (1mk)

e) Name the condition and reagents in step III

i) Condition (1mk)

ii) Reagent (1mk)

f) Calculate the mass of salt Q that would be formed by using 21.9kg of G when it reacts with excess sodium hydroxide (2mks)
(C = 120, H = 1.0, Na = 23.0, O = 16.0)

g) i) Draw the structure of polymer D (1mk)

ii) State one use of the above polymer (1mk)

A volume of 80cm3 of a mixture of propane (C3H8) and oxygen were ignited in an experiment. The products were cooled and passed through an aqueous sodium hydroxide. The final volume was reduced by 30cm3

A volume of 80cm³ of a mixture of propane (C₃H₈) and oxygen were ignited in an experiment. The products were cooled and passed through an aqueous sodium hydroxide. The final volume was reduced by 30cm³

a) Write the equation for the combustion of propane (1mk)

b) Determine the volume of;

i) The component of the original mixture (2mks)

ii) Residual oxygen (1mk)

Chemistry Topics

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Author

The following set – up was made in an experiment by a group of form four students. The readings of the balance before and after experiment were indicated in the diagram below.

​Determine:

​a) Temperature change that occurred (1mk)

​b) Amount of ethanol used (1mk)

​c) Moles of ethanol used (2mks)

​d) Amount of heat gained by water (2mks)

​e) Molar enthalpy of combustion of ethanol (2mks)

​f) Use the following thermochemical processes to answer the questions that follow;

​i) Draw an energy level diagram representing the formation and combustion processes of propane, carbon and hydrogen (2mks)

​ii) Hence or otherwise, determine the heat of formation of propane (2mks)

Use the flow chart below to answer the questions that follow

​​a) Name the following;

​i) Gas L (1mk)

​ii) Gas H (1mk)

​iii) K (1mk)

​​b) Name the processes involved in the following steps

​i) Step I (1mk)

​ii) Step II (1mk)

​​iii) Step III (1mk)

​c) Draw the structure of compound E (1mk)

​d) Write a chemical equation for the complete combustion of substance F (1mk)

​e) Name the condition and reagents in step III

​i) Condition (1mk)

​ii) Reagent (1mk)

​f) Calculate the mass of salt Q that would be formed by using 21.9kg of G when it reacts with excess sodium hydroxide (2mks) (C = 120, H = 1.0, Na = 23.0, O = 16.0)

​g) i) Draw the structure of polymer D (1mk)

​ii) State one use of the above polymer (1mk)

A volume of 80cm3 of a mixture of propane (C3H8) and oxygen were ignited in an experiment. The products were cooled and passed through an aqueous sodium hydroxide. The final volume was reduced by 30cm3

A volume of 80cm3 of a mixture of propane (C3H8) and oxygen were ignited in an experiment. The products were cooled and passed through an aqueous sodium hydroxide. The final volume was reduced by 30cm3

a) Write the equation for the combustion of propane (1mk)

b) Determine the volume of;

i) The component of the original mixture (2mks)

ii) Residual oxygen (1mk)

Chemistry Topics

Archives

Author

Determine:

a) Temperature change that occurred (1mk)

b) Amount of ethanol used (1mk)

c) Moles of ethanol used (2mks)

d) Amount of heat gained by water (2mks)

e) Molar enthalpy of combustion of ethanol (2mks)

f) Use the following thermochemical processes to answer the questions that follow;

i) Draw an energy level diagram representing the formation and combustion processes of propane, carbon and hydrogen (2mks)

ii) Hence or otherwise, determine the heat of formation of propane (2mks)

a) Name the following;

i) Gas L (1mk)

ii) Gas H (1mk)

iii) K (1mk)

b) Name the processes involved in the following steps

i) Step I (1mk)

ii) Step II (1mk)

iii) Step III (1mk)

c) Draw the structure of compound E (1mk)

d) Write a chemical equation for the complete combustion of substance F (1mk)

e) Name the condition and reagents in step III

i) Condition (1mk)

ii) Reagent (1mk)

f) Calculate the mass of salt Q that would be formed by using 21.9kg of G when it reacts with excess sodium hydroxide (2mks)
(C = 120, H = 1.0, Na = 23.0, O = 16.0)

g) i) Draw the structure of polymer D (1mk)

ii) State one use of the above polymer (1mk)

A volume of 80cm³ of a mixture of propane (C₃H₈) and oxygen were ignited in an experiment. The products were cooled and passed through an aqueous sodium hydroxide. The final volume was reduced by 30cm³