Consider the following thermochemical equation:
CH4(g) + I2(g) --> CH3I(g) + HI(g) DH = +23 kJ
What energy change occurs when 1.6 mol of CH4 reacts?
23 kJ x 1.6 mol = ?
To determine the energy change that occurs when 1.6 mol of CH4 reacts, we need to use the given thermochemical equation and the concept of stoichiometry.
First, let's determine the balanced equation for the reaction:
CH4(g) + I2(g) --> CH3I(g) + HI(g)
From the equation, we can see that the stoichiometric coefficient for CH4 is 1. This means that for every 1 mole of CH4, we will have an energy change of +23 kJ.
Since we are given 1.6 mol of CH4, we can set up a proportion to find the energy change:
(1.6 mol CH4 / 1 mol CH4) = (x kJ / 23 kJ)
Solving this proportion will give us the value of x, which represents the energy change:
x = (1.6 mol CH4 / 1 mol CH4) * 23 kJ
x = 36.8 kJ
Therefore, the energy change that occurs when 1.6 mol of CH4 reacts is +36.8 kJ.