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Chapter 3, NCERT (CBSE) Science (Chemistry) Atoms and Molecules   In text Questions NCERT Science Text Book Page 32 Q.1: In a reaction, 5.3 gm of sodium carbonate reacted with 6 gm of ethanoic acid. The products were 2.2 gm of carbon dioxide, 0.9 gm water and 8.2 gm sodium ethanoate. Show that these observations are in agreement with the law of conservation of mass.      Ans: Mass of

CBSE Science, Class 9, Atoms and Molecules   NCERT Solutions of Science  Textbook Chapter Exercise Questions Solved    Q.1: A 0.24 gm sample of compound of oxygen and boron was found by analysis to contain 0.096 gm of boron and 0.144 gm of oxygen. Calculate the percentage composition of the compound by weight.   Ans: % of boron in sample = (0.096 ÷ 0.24) × 100 = 40%         % of oxygen in

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