Question

How much heat is absorbed/released when 20.00 g of NH3(g) reacts in the presence of excess O2 (g) to produce NO (g) and H2O (l) according to the following chemical equation?4NH3 (g) + 5O2 (g) ---> 4NO (g) +6H2O (l) Δ H: +1168 kJa. 342.9 kJ of heat are absorbed.b. 342.9 kJ of heat are released.c. 1372 kJ of heat are absorbed.d. 1372 kJ of heat are released.

Answer 1

Answer:

a. 342.9 kJ of heat are absorbed.

Explanation:

Calculation of the moles of $NH_3$ as:-

Mass = 20.00 g

Molar mass of $NH_3$ = 17.031 g/mol

The formula for the calculation of moles is shown below:

$moles = \frac{Mass\ taken}{Molar\ mass}$

Thus,

$Moles= \frac{20.00\ g}{17.031\ g/mol}$

$Moles= 1.1743\ mol$

Given that:- $\Delta H=+1168\ kJ$

It means that 1 mole of $NH_3$ undergoes reaction and absorbs 1168\ kJ of heat

So,

1168 mole of $NH_3$ undergoes reaction and absorbs $1168\times 1168\ kJ$ of heat

Amount of heat absorbed = + 342.9 KJ