NCERT Solutions for Science Class 9 Chapter 3

Chapter 3: Atoms and Molecules

Intext Exercise 1

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

Sodium Carbonate + ethanoic acid → sodium rthanoate + carbon dioxide + water

Answer: 

Given,

Mass of sodium carbonate \(=5.3\space g\)

Mass of ethanoic acid \(=6\space g\)

Mass of carbon rthanoate \(=8.2\space g\)

Mass of carbon dioxide \(=2.2\space g\)

Mass of water \(=0.9\space g\)

Now, total mass after the reaction \(=(5.3+6)\space g=11.3\space g\)