# If 1.4 G of Calcium Oxide is Formed by the Complete Decomposition of Calcium Carbonate, Then the Amount of Calcium Carbonate Taken and the Amount of Carbon Dioxide Formed Will Be Respectively : - Science

MCQ
Short Note

If 1.4 g of calcium oxide is formed by the complete decomposition of calcium carbonate, then the amount of calcium carbonate taken and the amount of carbon dioxide formed will be respectively :

#### Options

• 2.2 g and 1.1 g

• 1.1 g and 2.5 g

• 2.5 g and 1.1 g

• 5.0 g and 1.1 g

#### Solution

2.5 gm and 1.1 gm

Molecular mass of CaCO3: 40 + 12 + (16 × 3) = 100g
Molecular mass of CaO: 40 + 16 = 56g
Molecular mass of CO2: 12 + (16 × 2) = 44g
Reaction for the decomposition of calcium carbonate:

CaCo3 → CaO + CO2

100g      56g    44g
X          1.4g     Y

56 g of CaO is obtained when 100g of CaCO3 is burnt.
Therefore, to get 1.4g of CaO, the amount of CaCO3 to be burnt will be

(100xx1.4)/56 =2.5g

For CO2,
100g of CaCO3 yields 44g of CO2
Therefore, 2.5g of CaCO3 will yield;

44xx2.5/100 = 1.1 "g"

Concept: Difference Between Atoms and Molecules
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#### APPEARS IN

Lakhmir Singh Class 9 Chemistry - Science Part 2
Chapter 3 Atoms and Molecules
Multiple Choice Questions | Q 65 | Page 131