Question

When 1.50 mol of CH 4( g) reacts with excess Cl 2( g) at constant pressure according to the chemical equation shown below, 1062 kJ of heat are released. Calculate the value of Δ H for this reaction, as written. 2 CH4(g) + 3 Cl2(g) → 2 CHCl3(l) + 3 H2(g)ΔH = ?

Answer 1

If 1.50 mol of CH₄ release 1062 kJ

in the equation 2 CH4(g) + 3 Cl2(g) → 2 CHCl3(l) + 3 H2(g) you have 2 moles of CH₄

So, you just need to use the rule of 3 to answer it:

1.50 mol of CH₄ ------- 1062 kJ

2.00 mol of CH₄ ------ x

1.5x = 2 × 1062

x = 2124/1.5

x = 1416 kJ

ΔH for this reaction is 1416 kJ.