Question

How many grams of solid calcium carbonate must decompose to produce solid calcium oxide and 534.0 mL carbon dioxide gas at 298°C and 729 torr?

Answer 1

Balanced equation:
CaCO₃ = CaO + CO₂

PV = nRT

where:

P is the pressure of the gas = 729 torr = 0.9592 atm

V is the volume of the gas = 0.534 Liter

n is the amount of substance of gas (in moles) = ?

R is gas constant = = 0.0821 L atm K-1 Mol-1

T is the absolute temperature of the gas = 273 + 278 = 551 K

substitute in the equation and calculate moles

n = 0.9592 x 0.537 / 0.0821 x 551 = 0.011322 Moles

0.011322 Moles of CO2 need to be produced

According to the equation

Moles of CaCO3 is needed = 0.011322

Mass of CaCO3 = 0.011322 x 100.08 = 1.133 gm

Hence 1.133 gm of CaCO3 is needed to produce 534.0 mL carbon dioxide gas at 298°C and 729 torr

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