a)
i. Zinc blende (penalize zinc sulphide )
ii. ZnO
iii. Reduction using carbon or carbon (II) oxide
iv. It is converted to zinc sulphate and electrolyzed
b)
- Sulphur {IV} oxides/SO2
- Carbon {IV} oxide /CO2
c)
- Sulphur {IV} oxide leads to formation of acid rain
- Carbon oxide causes global warming
d)
- Zinc is used to galvanise iron to prevent it form rusting
- To make brass an alloy of copper and zinc
marto answered the question on October 11, 2019 at 11:12
- The information below gives PH values of solutions V, W, X, Y Z(Solved)
The information below gives PH values of solutions V, W, X, Y Z
(a) Which solution is likely to be:
(i) Calcium hydroxide?
(ii) Rain water?
(b) Which solution would react most vigorously with Zinc carbonate
Date posted: October 11, 2019. Answers (1)
- The diagram below shows the contact process used in the manufacture of concentrated sulphuric(vi) acid.(Solved)
The diagram below shows the contact process used in the manufacture of concentrated sulphuric(vi) acid.
a) Identify the following:
i) Substance Q formed in the burner
ii) Chamber T
iii) Substance R
iv) Substance S
ii) Write the chemical equation occurring in the dilution chamber.
iii) Why is it necessary to pass substance Q though a purifier.
iv) State one use of sulphuric (VI) acid.
Date posted: October 11, 2019. Answers (1)
- The diagram below shows the process used to obtain Sulphur from underground deposits.(Solved)
The diagram below shows the process used to obtain Sulphur from underground deposits.
i) Name the above process used to obtain sulphur from the underground deposits
ii) Name the substance passed through pipe
A
B
iii) State two properties of Sulphur that makes it possible to extract using the above process.
Date posted: October 11, 2019. Answers (1)
- The table below shows solutions A, B and C are tested and observations records as shown:(Solved)
The table below shows solutions A, B and C are tested and observations records as shown:
(a) Using the table above, name an acid
(b) How does the pH value of 1M potassium hydroxide solution compare with that of
1M aqueous ammonia? Explain
Date posted: October 11, 2019. Answers (1)
- a)Name two apparatuse that can be used for determining mass in a laboratory.(Solved)
a)Name two apparatus that can be used for determining mass in a laboratory.
(b) One of the flames produced by Bunsen burner is the luminous flame.
i) Explain why this flame is very bright
ii) State two disadvantages of the luminous flame.
(c) Air is usually one of the substances that is considered as a mixture.
(i) Identify the two most abundant component of air.
(ii) Give two reasons why the air is considered as a mixture.
(iii) One of the components of air is carbon (iv) oxide. Describe an experiment that can be used to prove the presence of carbon (iv) oxide in the air.
Date posted: October 11, 2019. Answers (1)
- Name the following compounds
(i) CH3CH2CH2COOH(Solved)
Name the following compounds
(i) CH3CH2CH2COOH
(iii)CH3CH2OOCCH2CH3
b) Two types of detergents P and Q can be represented as
(i) Identify each type of the detergent.
(ii) Which of the two detergents is the best to use with hard water? Give a reason.
(iii) State one advantage of detergent P.
(iv) State one disadvantage of detergent Q.
(c) An hydrocarbon can be represented as follows.
(i) Identify the hydrocarbon
(ii) Name two reagents that can reacted together to generate the hydrocarbon
Date posted: October 11, 2019. Answers (1)
- The setup below was used to separate two miscible liquids Q and T
(Boling points; Q =98° C, T=78°C)(Solved)
The setup below was used to separate two miscible liquids Q and T
(Boling points; Q =98° C, T=78°C)
(a) Identify the mistakes in the setup above
(b)Identify Distillate X
Date posted: October 11, 2019. Answers (1)
- The grid below shows a section of the periodic table, the letters are not the actual chemical symbol(Solved)
The grid below shows a section of the periodic table, the letters are not the actual chemical symbol
a) Name the family into which element P belongs to.
b) Which two elements forms the most soluble carbonates
c) With a reason, identify elements in period 3 with the largest atomic radius
d) Write the formula of the compound formed between Q and M
e) State two uses of element R and for each use , state property of element R that makes lts possible for the use
(i) Use
Property
(ii) Use
Property
f) Using dots and cross ,show bonding in the compound formed between R and oxygen.
g) In terms of structure and bonding explain why the oxides of element Thas relatively low boiling points
Date posted: October 11, 2019. Answers (1)
- Given a mixture of lead (II) oxide, ammonium chloride and sodium chloride, describe how this mixture can be separated to obtain a sample of each.(Solved)
Given a mixture of lead (II) oxide, ammonium chloride and sodium chloride, describe how this mixture can be separated to obtain a sample of each.
Date posted: October 11, 2019. Answers (1)
- Study the information below and answer the questions that follow:(Solved)
Study the information below and answer the questions that follow:
Describe how the mixture of solid R, S, and V can be separated
Date posted: October 11, 2019. Answers (1)
- The set-up below was used to separate a mixture:-(Solved)
The set-up below was used to separate a mixture:-
(a) Name the apparatus missing in the set-up
(b) Give one example of mixture T
(c) What is the name of this method of separation
Date posted: October 11, 2019. Answers (1)
- A student left some crushed fruit mixture with water for some days. He found the mixture had fermented. He concluded that the mixture was contaminated...(Solved)
A student left some crushed fruit mixture with water for some days. He found the mixture had fermented. He concluded that the mixture was contaminated with water and ethanol with boiling point of 100oC and 78oC respectively. The set-up of apparatus below are used to separate the mixture.
(i) Name the piece of apparatus labelled W
(ii) What is the purpose of the thermometer in the set-up?
iii) At which end of the apparatus W should tap water be connected?
(iv) Which liquid was collected as the first distillate? Explain
(v) What is the name given to the above method of separating mixture?
(vi) State two applications of the above method of separating mixtures
(vii) What properties of the mixture makes it possible for the component to be separated by the above methods?
Date posted: October 11, 2019. Answers (1)
- State two criteria for determining the purity of a substance(Solved)
State two criteria for determining the purity of a substance
Date posted: October 11, 2019. Answers (1)
- Classify the following processes as chemical changes or physical changes(Solved)
Classify the following processes as chemical changes or physical changes
Process physical or chemical
Neutralization ………………………………………
Sublimation ………………………………………
Fractional distillation ………………………………………..
Displacement reaction …………………………………………
Date posted: October 11, 2019. Answers (1)
- The apparatus below were used by a student to study the effect of heat on hydrated copper II sulphate(Solved)
The apparatus below were used by a student to study the effect of heat on hydrated copper II sulphate
(a) What is the role of the ice cold water
(b) Name liquid P
(c) What observation is made in the boiling tube
Date posted: October 11, 2019. Answers (1)
- A form 1 student carried out the separation as shown in the set-up below:-(Solved)
A form 1 student carried out the separation as shown in the set-up below:-
(i) Identify the method above.
(ii) Give one of its disadvantages
(iii) Name a mixture which can be separated by the set-up above
Date posted: October 11, 2019. Answers (1)
- Cooking oils comprise of a mixture of compounds which have a boiling point range
of 23oC to 27oC.
(i) What evidence is then to support the statement...(Solved)
Cooking oils comprise of a mixture of compounds which have a boiling point range
of 23oC to 27oC.
(i) What evidence is there to support the statement that cooking oil is a mixture?
(ii)Name another experimental technique that could be used to confirm your answer in part (i) above
Date posted: October 11, 2019. Answers (1)
- Without using any laboratory chemical, describe a simple laboratory experiment to distinguish between calcium hydrogen carbonate and sodium hydrogen carbonate.(Solved)
Without using any laboratory chemical, describe a simple laboratory experiment to distinguish between calcium hydrogen carbonate and sodium hydrogen carbonate.
Date posted: October 11, 2019. Answers (1)
- The two elements P and R were separately burned in air, the products gave the results recorded in the table below:(Solved)
The two elements P and R were separately burned in air, the products gave the results recorded in the table below:
(a) Suggest the identity of element R.
(b) Describe how the nature of the solutions of the of the oxides were determined
Date posted: October 11, 2019. Answers (1)
- It is advisable to set a Bunsen burner to luminous flame prior to an experiment.
Explain(Solved)
It is advisable to set a Bunsen burner to luminous flame prior to an experiment.
Explain
Date posted: October 11, 2019. Answers (1)