Question

g Ammonium nitrate was the oxidizing agent used that damaged the New York World Trade Center in 1993 and the Federal Building in Oklahaoma City in 1995. The thermochemical equation for its decomposition is given below. What quantity of heat is evolved from the decomposition of 50.0 kg of ammonium nitrate

Answer 1

Answer:  $51.3\times 10^3$ kJ

Explanation:

The thermochemical equation for decomposition of ammonium nitrate is:

$NH_4NO_3(s)\rightarrow N_2O(g)+2H_2O(g)$   $\Delta H=-82.1kJ$

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$

Given mass= 50.0 kg =$50.0\times 10^3g$   (1kg=1000g)

$\text{Number of moles of ammonium nitrate}=\frac{50.0\times 10^3g}{80g/mol}=0.625\times 10^3moles$

According to stoichiometry:

1 mole of $NH_4NO_3$ gives = 82.1 kJ of heat

Thus $0.625\times 10^3moles$ of $NH_4NO_3$ give =$\frac{82.1}{1}\times 0.625\times 10^3=51.3\times 10^3$  kJ of heat

Thus $51.3\times 10^3$ kJ of heat is evolved from the decomposition of 50.0 kg of ammonium nitrate.