Question

What mass of carbon monoxide must be burned to produce 175 kj of heat under standard state conditions?

Answer 1

When 2.50 g is burned then in oxygen then 1.25kj of heat is produced.

Answer 2

Answer:

17.3 g

Explanation:

Let's consider the combustion of CO.

CO(g) + 0.5 O₂(g) → CO₂(g)

We can find the standard enthalpy of the reaction using the following expression.

ΔH°rxn = 1 mol × ΔH°f(CO₂(g)) - 1 mol × ΔH°f(CO(g)) - 0.5 mol × ΔH°f(O₂(g))

ΔH°rxn = 1 mol × (-393.5 kJ/mol) - 1 mol × (-110.5 kJ/mol) - 0.5 mol × 0

ΔH°rxn = -283.0 kJ

283.0 kJ are released per mole of CO. The moles of CO required to release 175 kJ are:

(-175 kJ) × (1 mol CO/ -283.0 kJ) = 0.618 mol CO

The molar mass of CO is 28.01 g/mol. The mass of CO is:

0.618 mol × (28.01 g/mol) = 17.3 g