Chapter 3: Atoms and Molecules

Science

(www.olympiadsuccess.com)

Chapter 3: Atoms and Molecules

Class: IX

Exercise number 32

Question 1

In a reaction 5.3 g of sodium carbonate reacted with 6 g of ethanoic acid. The products were 2.2 g of carbon dioxide, 0.9g water and 8.2 g of sodium ethanoate. Show that these observations are in agreement with the law of conservation of mass.

Sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water

Answer 1

Sodium carbonate + ethanoic acid → sodium ethanoate + carbon dioxide + water

Given that,

Mass of sodium carbonate = 5.3g

Mass of ethanoic acid = 6g

Mass of sodium ethanoate = 8.2g

Mass of carbon dioxide = 2.2

Mass of water = 0.9g

Total mass before the reaction = Mass of sodium carbonate + Mass of ethanoic acid

= (5.3 + 6)g = 11. 3g

Total mass after the reaction = Mass of sodium ethanoate + Mass of CO₂  + Mass of water

= (8.2 + 2.2 + 0.9)g = 11.3g

Therefore, Total mass before the reaction = Total mass after the reaction

Hence,  we can say that the given observations agree with the law of conservation of mass.