Question

A sample of 3 g containing Na CO2 and NaHCO3 loses 0.248 g when heated to 300°C, the
temperature at which NaHCO3 decomposes to Na CO2, CO, and H20. What is the percentage
of Na Coz in the given mixture ?
2NaHCO3(s) - A Na, CO3(s) + CO2(g) + H2O(g)​

Answer 1

Answer:

We can write a balanced chemical equation as:

168g

2NaHCO

3

→Na

2

CO

3

+

44

CO

2

+

18

H

2

O

The loss comes due to evolution of CO

2

and steam.

62 g loss occurs when the quantity of NaHCO

3

is 168 g.

0.248 g loss will occur when the quantity of NaHCO

3

= 62

168×0.248=0.672g

Quantity of Na

2 CO 3 in the sample =(2.0−0.672)=1.328g% of Na

2 CO3

= 2

1.328 ×100=66.4