Question

in the following reaction, what quantity in moles of ch₃oh is required to give off 4221 kj of heat?
co₂(g) + 4h₂o(g) δh° = -1280. kj/mol

Explanation:

Step1: Set up the proportion

Let \(n\) be the number of moles of \(CH_3OH\). We know that for \(1\) mole of \(CH_3OH\), the heat change \(\Delta H=- 1280\space kJ/mol\). So the proportion is \(\frac{1\space mol}{1280\space kJ}=\frac{n}{4221\space kJ}\).

Step2: Solve for \(n\)

Cross - multiply: \(n=\frac{4221\space kJ\times1\space mol}{1280\space kJ}\).
Calculate \(n\approx3.3\space mol\).

Answer:

\(3.3\space mol\)