Calculate the volume of carbon monoxide (4) if 5 kg of coal containing 20% impurities is burned.

1. Let’s compose the equation of the chemical reaction:

C + O2 = CO2.

2. Find the chemical amount of coal:

5 kg = 5000 g.

ω (C) = 100% – ω (impurities) = 100% – 20% = 80%.

m (C) = m (mixture) * ω (C) / 100% = 5000 g * 80% / 100% = 4000 g.

n (C) = m (C) / M (C) = 4000 g / 12 g / mol = 333.3 mol.

3. According to the reaction equation, we find the chemical amount of carbon monoxide, and then its volume (Vm is the molar volume, constant equal to 22.4 l / mol):

n (CO2) = n (C) = 333.3 mol.

V (CO2) = n (CO2) * Vm = 333.3 mol * 22.4 L / mol = 7466.7 L.

Answer: V (CO2) = 7466.7 liters.