Question

When dilute sulphuric acid is added to a solid X, a gas Y is formed which puts off the burning

match stick along with the formation of the salt of the solid. Which of the following could be

X and Y? Justify your choice 2M

a) X is Zn, Y is CO2

b) X is Zn, Y is O2

c) X is Zn, Y is H2

d) X is Zn, Y is ZnO​

Answer 1

Answer:

c part

Explanation:

When sodium carbonate reacts with sulphuric acid, it produces carbon dioxide gas with effervescence.

Carbon dioxide is used as fire extinguisher.

Hence, it extinguishes a burning candle.

Therefore, the metal compound A is sodium carbonate.

Answer 2

Option (c) - X is Zn and Y is H₂.

Explanation:

When hydrogen reacts with the oxygen present in the atmosphere, it explodes with a pop sound. This small explosion extinguishes the burning matchstick or a candle.

When Zn comes in contact with dilute sulphuric acid it liberates hydrogen gas at room temperature.

$Zn + H_{2} SO_{4} (dil) \rightarrow ZnSO_{4}+H_{2}$

Note that when Zn is heated with concentrated sulphuric acid, sulphur dioxide is liberated.

$Zn + 2H_{2} SO_{4} (conc) \rightarrow ZnSO_{4}+SO_{2}+2H_{2} O$