Question

16. When 25.2 g of Sodium bicarbonate is heated, we will get 5.3 g of Sodium carbonate, 2.2 g of Carbon
dioxide and 0.9 g of water along with some amount of undecomposed Sodium bicarbonate. The mass
of Sodium bicarbonate left undecomposed is :
(1) 8.4 g
(2) 4.2 g
(3) 16.8 g
(4) Cannot be predicted

Answer 1

Answer:

By the law of conservation of mass,

sum of mass of reactant=sum of the mass of products

25.2=5.3+2.2+0.9,+x

25.2-(5.3+2.2+0.9) =x

25.2-8.4=x

x=16.8

thus mass is sodium bicarbonate is 16.8g