Question

CLASS 9
"ATOMS AND MOLECULES"
Question : What mass of CO2 is released if 10g of calcium carbonate decomposes to form 6.2g of calcium oxide and carbon dioxide. CaCO3 -- decomposition → CaO + CO2

Answer 1

Answer :-

3.8 grams of CO₂ is released .

Explanation :-

We have :-

→ Mass of Calcium Carbonate = 10 g

→ Mass of Calcium Oxide = 6.2 g

________________________________

CaCO₃ → CaO + CO₂

The above given reaction is a decomposition reaction, in which :-

• Calcium Carbonate (CaCO₃) is reactant .

• Calcium Oxide (CaO) and Carbon dioxide (CO₂) are products .

________________________________

According to "Law of Conservation of Mass", we know that :-

Mass of Reactants = Mass of Products

Let the required mass of carbon dioxide be x grams .

⇒ 10 = 6.2 + x

⇒ x = 10 - 6.2

⇒ x = 3.8 g

Answer 2

Given :-

CaCO₃ ⇒ CaO + CO₂

To Find :-

Mass of CO₂

Solution :-

In other words, it can be written as

Calcium carbonate ⇒ Calcium oxide + Carbon dioxide

We know that

LHS = Reactant

RHS = Product

Since,

Mass of product = Mass of reactant

10 = CO₂ + 6.2

10 - 6.2 = CO₂

3.8 = CO₂