Carbon and some of its Compounds questions and answers
QUESTION 1.
Give two properties of carbon (IV) oxide which make it suitable for use in
extinguishers.
ANSWER
- Dense than air
- Does not burn
- Put off the burning flame
QUESTION 2.
Give a reason why calcium hydroxide solution is used to detect the presence of
Carbon (IV) oxide gas while sodium hydroxide sodium is NOT?
ANSWER
Ca(OH)2 produces CaCO3 which is insoluble.
NaOH forms Na2Co3 which is
soluble.
QUESTION 3.
Explain how you would obtain solid sodium carbonate from a mixture of lead
carbonate powder.
ANSWER
Add water and stir. Sodium carbonate will dissolve. Filter to get lead carbonate
as a residue
QUESTION 4.
When extinguishing a fire caused by burning kerosene, carbon (IV) oxide is used
in preference to water. Explain
ANSWER
Kerosene is less dense and floats spreading the fire. CO2 is dense and covers
the fire preventing oxygen from reaching the fire.
QUESTION 5.
When dilute nitric acid was added to a sample of solid “C” a colourless gas that
formed a white precipitate with lime water was produced.
When another sample
of solid “C” was heated strongly in a test tube, there was no observations changes.
Write the formula of the ions in solid “C”
ANSWER
K+
/ Na+ and CO3
-2
QUESTION 6.
The diagram below represents a charcoal burner. Study it and answer the
questions that follow:
Write equations for the reactions taking place at I and II
ANSWER
i) C(s) + O2(s) CO2(g)
ii) CO2(g) + C(s) 2CO(s)
QUESTION 7.
When excess carbon (IV) oxide passed over heated lead (II) oxide in combustion
tube, lead (II) oxide was reduced.
a) Write an equation for the reaction which took place. (1mk)
b) What observations were made in the combustion tube when the reaction
was complete? (1mk)
c) Name another gas that would be used to reduce lead (II) oxide.
ANSWER
a) PBO(s) + CO(s) => Pb(s) + CO2(g)
b) Colour of PbO changes from yellow when cold, brown when hot, and Finally
grey.
c) Hydrogen gas
QUESTION 8.
State any two differences between the luminous flame and non-luminous flame.
ANSWER
Luminous
-Sooty flame
-Produce more light
-Less heat
-Weavy flame
Non-luminous
- Non-sooty
- Produce Less light
- very hot
- Stead flame
QUESTION 9.
a) Explain the following
i) Temporary hardness in water
ii) Permanent hardness in water.
b) i) Draw a diagram and explain how the ionic exchanger works.
ii) Explain why hard water is recommended for the healthy development
of teeth.
ANSWER
a) Hardness caused by soluble Ca2+ + /mg2+
HCO2- salts can be removed by warming.
b) Hardness caused by soluble CaSO4 cannot be removed by warming.
Contain Ca2+
(aq) + Na+
p(s) → Na +(aq) + Cap (s)
NOTE: Questions are updated daily; come for more knowledge.
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