An industrial furnace must absorb exactly 750 kJ of energy by decomposing ammonium nitrate

CHEMISTRY · Single correct · A Level · Chemistry · Energetics · Energetics

Problem

An industrial furnace must absorb exactly 750 kJ of energy by decomposing ammonium nitrate, a process whose molar enthalpy change is

\Delta H_{\text{rxn}}=+25.4\,\text{kJ}\,\text{mol}^{-1}

. Which expression correctly relates the number of moles

n

of ammonium nitrate required to the heat

q

that must be absorbed? (a)

n = -\dfrac{q}{\Delta H_{\text{rxn}}}

(b)

n = \dfrac{q}{\Delta H_{\text{rxn}}}

(c)

n = \dfrac{2q}{\Delta H_{\text{rxn}}}

(d)

n = \dfrac{q}{1000\,\Delta H_{\text{rxn}}}