Question

A 20 G of impure sample nahco3 on heating gave 2.27 litre carbon dioxide at STP calculate the percentage purity of the sample​

Answer 1

Answer:

50

Sodium bicarbonate decomposes in

the following manner.

2NaHCO

3

→Na

2

CO

3

+H

2

O+CO

2

Sodium Carbonate is stable and

doesn't dissociate upon normal

heating.

Vol. of CO

2

=224ml

22.4Ltr=1mole

So moles of CO

2

=0.224/22.4=0.01mole

0.01mole=44×0.01g=0.44g

1 mole CO

2

is procured by 2 mole NaHCO

3

∴ Moles of NaHCO

3

=2×0.01=0.02

=0.02×84=1.689

% age =

Totalmass

mass

×100=

2

1.68

×100=84%

Answer 2

Answer:

Sodium bicarbonate decomposes in

the following manner.

2NaHCO

3

→Na

2

CO

3

+H

2

O+CO

2

Sodium Carbonate is stable and

doesn't dissociate upon normal

heating.

Vol. of CO

2

=224ml

22.4Ltr=1mole

So moles of CO

2

=0.224/22.4=0.01mole

0.01mole=44×0.01g=0.44g

1 mole CO

2

is procured by 2 mole NaHCO

3

∴ Moles of NaHCO

3

=2×0.01=0.02

=0.02×84=1.689

% age =

Totalmass

mass

×100=

2

1.68

×