Page 2 - HOME ASSIGNMENT-2 (PRACTICE WORKSHEET)

DIRECTION:Each of these questions contains an Assertion followed by
Reason. Read them carefully and answer the question on the basis of
following options. You have to select the one that best describes the two
statements.
(a) If both Assertion and Reason are correct and Reason is the correct
explanation of Assertion.
(b) If both Assertion and Reason are correct, but Reason is not the correct
explanation of Assertion.
(c) If Assertion is correct but Reason is incorrect.

(d) If Assertion is incorrect but Reason is correct.
(e) If Assertion & Reason both are incorrect.
Q.4 Assertion (A) : Sodium metal is stored under Kerosene.
Reason(R) : sodium melts when exposed to air.

Q.5 Assertion : Weak acids have low electrical conductivity.
Reason : Strong acids and weak acids have equalconcentration of hydrogen ions in
their solutions.

Q.6 (a) Why is it necessary to balance a chemical equation?
(b) Write the balanced chemical equation for the following reactions:
(i) Natural gas burns in air to form carbon dioxide and water.
(ii) During respiration, glucose combines with oxygen and forms carbon
dioxide and water along with the release of energy.

Q.7 Explain the action of dilute hydrochloric acid on the following with suitable chemical
equations:
a. Magnesium ribbon,
b. Sodium hydroxide,
c. Crushed egg shells.

Q.8 State the reason for the following statements:
a. Tap water conducts electricity whereas distilled water does not.
b.Dry hydrogen chloride gas does not turn blue litmus red whereas dilute
hydrochloric acid does.
c. During summer season, a milkman usually adds avery small amount of
baking soda to fresh milk.
d. For dilution of an acid, acid is added to water andnot water to acid.
e. Ammonia is a base but it does not contain hydroxyl group.

Q.9 On heating blue coloured powder of copper (II) nitrate in a boiling tube, copper
oxide (black), oxygen gas and a brown gas X is formed:
(a) Write a balanced chemical equation of the reaction.
(b) Identity the brown gas X evolved.
(c) Identity the type of reaction.
(d) What could be nature of aqueous solution of the gas X?

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