Get premium membership and access questions with answers, video lessons as well as revision papers.
Brown fumes of a gas are produced as the charcoal dissolves in the acid. The charcoal reduces nitric (V) acid to nitrogen (IV) oxide gas that is brown while the charcoal is oxidized to carbon (IV) oxide.
maurice.mutuku answered the question on October 17, 2019 at 05:09
- The diagram below shows the heating curve of a pure substance. Study it and answer the questions that follow:(Solved)
The diagram below shows the heating curve of a pure substance. Study it and answer the questions that follow:
(a) Explain what happens between points A and C
(b) The substance under test is definitely not water; Give a reason for this
(c) What would happen to the melting point of this substance if it were contaminated with sodium chloride?
(d) What happens to the temperature between points B and C?
Date posted: October 16, 2019. Answers (1)
- Diamond and silicon (IV) Oxide have a certain similarity in terms of structure and bonding.
State it(Solved)
Diamond and silicon (IV) Oxide have a certain similarity in terms of structure and bonding.
State it
Date posted: October 16, 2019. Answers (1)
- Study the diagram below and use it to answer the questions that follow.(Solved)
Study the diagram below and use it to answer the questions that follow.
(a) State the observation made in the combustion tube.
(b) Write an equation for the reaction that took place in the combustion tube
(c) Give one use of P
Date posted: October 16, 2019. Answers (1)
- Below is part of a flow diagram for the contact process:(Solved)
Below is part of a flow diagram for the contact process:
(a) Name :
I. Liquid Y
II. Liquid N
(b) Write the equation for the reaction taking place in;
I. Chamber Q
II. Chamber R
Date posted: October 16, 2019. Answers (1)
- The diagram show an experiment for investigating electrical conduction in lead (II) fluoride. Study it and answer the questions that follow:(Solved)
The diagram show an experiment for investigating electrical conduction in lead (II) fluoride. Study it and answer the questions that follow:
(a) On the diagram
(i) Label the anode and the cathode
(ii) Complete the diagram by indicating the condition that is missing but must be present for
electrical conduction to take place.
(b) Why is it necessary to leave a gap between the cork and the boiling tube?
(c) State the observations that are expected at the electrodes during electrical conduction and at the experiment
(d) Write equations for the reactions that take place at the electrodes
(e) Why should this experiment be carried out in a fume chamber?
Date posted: October 16, 2019. Answers (1)
- Study the scheme below and answer the questions which follow:(Solved)
Study the scheme below and answer the questions which follow:
Identify ;
(i) The cation present in solid S
(ii) The anion in solid S
(iii) Write an equation to show how solid S is heated in process T
Date posted: October 16, 2019. Answers (1)
- Starting with barium carbonate solid, dilute sulphuric acid and dilute nitric acid,describe how you would prepare dry barium sulphate solid(Solved)
Starting with barium carbonate solid, dilute sulphuric acid and dilute nitric acid,describe how you would prepare dry barium sulphate solid
Date posted: October 16, 2019. Answers (1)
- Define the following terms:
(a) Crystallization
(b) Salting out as used in soap making(Solved)
Define the following terms:
(a) Crystallization
(b) Salting out as used in soap making
Date posted: October 16, 2019. Answers (1)
- Differentiate between Electrolyte and non-electrolyte(Solved)
Differentiate between Electrolyte and non-electrolyte
Date posted: October 16, 2019. Answers (1)
- When an electric current was passed through two molten substances E and F in separate
voltmeters. The observations recorded below were made:-(Solved)
When an electric current was passed through two molten substances E and F in separate
voltmeters. The observations recorded below were made:-
Complete the table above
Date posted: October 16, 2019. Answers (1)
- The set-up was used to electrolyse Lead (II) bromide. Study it and answer the questions that follow;(Solved)
The set-up was used to electrolyse Lead (II) bromide. Study it and answer the questions that follow;
(a) Write an ionic equation for the reaction that occurred at the cathode
(b) State and explain what happened at the anode
Date posted: October 16, 2019. Answers (1)
- In an experiment the following solids were provided to form three students;(Solved)
In an experiment the following solids were provided to form three students; Ca(NO3)2(s),NaH2PO4(s); Mg(OH)Cl(s) and Fe(NH4)2(SO4)2. 6H2O. They were then told to dissolve the
given solids in differently in 20ml of water.
(a) Classify the given salts accordingly
(b) (i) Explain the process which takes place when FeCl3 is dissolved in water
(ii) A student placed a moist litmus paper on the product in (i) above. State and explain the observation made
Date posted: October 16, 2019. Answers (1)
- Name the process which takes place when:
(a) Anhydrous iron (III) chloride absorb water vapour from the air to form solution
(b) Zinc chloride vapour changes directly...(Solved)
Name the process which takes place when:
(a) Anhydrous iron (III) chloride absorb water vapour from the air to form solution
(b) Zinc chloride vapour changes directly to zinc chloride solid
Date posted: October 16, 2019. Answers (1)
- Potassium nitrate crystals in a test-tube were heated strongly for some time. State the observation made:
(a) When a glowing splint is introduced into the test-tube...(Solved)
Potassium nitrate crystals in a test-tube were heated strongly for some time. State the observation made:
(a) When a glowing splint is introduced into the test-tube during the heating
(b) At the end of the heating
Date posted: October 16, 2019. Answers (1)
- Study the flow chart below and answer the questions that follow(Solved)
Study the flow chart below and answer the questions that follow
a) Identify ;
i) gases C and B
ii) Ions likely to be presented in solid A
Date posted: October 16, 2019. Answers (1)
- A piece of marble chips was strongly heated in air for about 30 minutes. Some drops of water were added drop by drop to the...(Solved)
A piece of marble chips was strongly heated in air for about 30 minutes. Some drops of water were added drop by drop to the product when it was still warm.
Using equation, explain:
(i) What happens when the piece of marble chips is heated?
(ii) The reaction that takes place when water is added to the final warm product.
Date posted: October 16, 2019. Answers (1)
- A student poured sodium iodide solution into a small portion of solution Q, a yellow precipitate was formed.
Which ion was most likely in solution Q?
(Solved)
A student poured sodium iodide solution into a small portion of solution Q, a yellow precipitate was formed.
Which ion was most likely in solution Q?
Date posted: October 16, 2019. Answers (1)
- When exposed to air, crystals of hydrated sodium carbonate loses water of crystallizations;-
(i) Name this process
(ii) Write the formula of hydrated sodium carbonate(Solved)
When exposed to air, crystals of hydrated sodium carbonate loses water of crystallizations;-
(i) Name this process
(ii) Write the formula of hydrated sodium carbonate
Date posted: October 16, 2019. Answers (1)
- You are provided with the following:- solid lead (II) nitrate, magnesium oxide powder,dilute sulphuric (VI)acid and distilled water. Describe how you can prepare a dry...(Solved)
You are provided with the following:- solid lead (II) nitrate, magnesium oxide powder,dilute sulphuric (VI)acid and distilled water. Describe how you can prepare a dry sample of lead (II) sulphate
Date posted: October 16, 2019. Answers (1)
- The scheme below shows some reactions starting with magnesium oxide. Study it and answer the questions that follow:-(Solved)
The scheme below shows some reactions starting with magnesium oxide. Study it and answer the questions that follow:-
(i) Name the reagents used in steps 2 and 4
(ii) Write an equation for the reaction in step 3
(iii) Describe how a solid sample of anhydrous magnesium carbonate is obtained in step 5
Date posted: October 16, 2019. Answers (1)