Question

40g of a carbonate of an alkaline metal or alkaline earth metal containing some inert impurities was made to react with excess HCl solution. the liberated CO2 occupied 12.315L at 1atm and 300K.Mass of the impurity

Answer 1

Explanation:

The volume of carbon dioxide at STP can be calculated by using the formula

P

V

T

=

P

′

V

′

T

′

Therefore,

1

×

12.315

300

=

1

×

V

′

273

′

or,

V

′

=

11.2

L

at STP conditions.

This corresponds to

0.5

moles of carbon dioxide.

0.5

mol of carbon dioxide is produced from

0.5

mol of metal carbonate such as lithium carbonate.

L

i

2

C

O

3

+

2

H

C

l

→

2

L

i

C

l

+

H

2

O

+

C

O

2

0.5

mol of lithium carbonate corresponds to

0.5

×

7.39

=

37

g.