WELCOME TO SaraNextGen.Com

INTRODUCTION - Chapter 3 - Atoms & Molecules - Ncert Solutions class 9 - Science

Updated On 26-08-2025 By Lithanya


You can Download the INTRODUCTION - Chapter 3 - Atoms & Molecules - Ncert Solutions class 9 - Science with expert answers for all chapters. Perfect for Tamil & English Medium students to revise the syllabus and score more marks in board exams. Download and share it with your friends

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, 0.9 g 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:

In the given reaction, sodium carbonate reacts with ethanoic acid to produce sodium ethanoate, carbon dioxide, and water.

https://img-nm.mnimgs.com/img/study_content/curr/1/9/8/115/618/Chapter%203_html_mf3b97b2.gif

Mass of sodium carbonate = 5.3 g (Given)

Mass of ethanoic acid = 6 g (Given)

Mass of sodium ethanoate = 8.2 g (Given)

Mass of carbon dioxide = 2.2 g (Given)

Mass of water = 0.9 g (Given)

Now, total mass before the reaction = (5.3 + 6) g

= 11.3 g

And, total mass after the reaction = (8.2 + 2.2 + 0.9) g

= 11.3 g

∴Total mass before the reaction = Total mass after the reaction

Hence, the given observations are in agreement with the law of conservation of mass.