Question

Consider the reaction described by the following chemical equation.

Answer 1

Answer:

Q = -897 kJ/mol

Explanation:

From the given information:

The heat released Q = -65.9 kJ

To start with the molar mass of $H_2O_2$ = 2 × (molar mass of H) + 2 × (molar mass of O)

= (2 × 1.008) + (2 × 16.0 )

= 34.016 g/mol

However, given that:

mass of $H_2O_2$  2.50 g

The number of moles of $H_2O_2$  = $\dfrac{mass}{molar \ mass}$

$= \dfrac{2.5}{34.016}$

$= 7.349 \times 10^{-2} \ mol$

Finally; Using the formula:

$\Delta H = \dfrac{Q}{number \ of \ moles}\\ \\ Q = \dfrac{-65.9 \ kJ}{7.349 \times 10^{-2} \ mol}$

Q = -897 kJ/mol