Question

When solid CaCO3 is heated, it decomposes to give solid CaO and CO2 gas. A volume of 560 mL of gas is collected over water at a total pressure of 730 mmHg and 16 ∘C. The vapor pressure of water at 16 ∘C is 14 mmHg. CaCO3(s)→CaO(s)+CO2(g)

1)How many moles of CO2 gas were in the CO2 gas sample? Express your answer with the appropriate units

Answer 1

Use ideal gas equation for calculation of mole of gas

Ideal gas equation

PV = nRT             where, P = atm pressure= 730 - 14 = 716 mmHg = 0.9421 atm,

V = volume in Liter = 560 ml = 0.560 L

n = number of mole = ?

R = 0.08205L atm mol^-1 K^-1 =Proportionality constant = gas constant,

T = Temperature in K = 16⁰C = 273.15+ 16 = 289.15 K

We can write ideal gas equation

n = PV/RT

Substitute the value

n = (0.9421 X 0.560)/(0.08205X 289.15) = 0.0222 mole

0.0222 mole of CO₂ gas in sample