What is the standard enthalpy of formation of NH3 gas? N2(g)+3H2(g)→ 2NH3(g); ΔrH°=-92.4 kJ mol-1

Question

What is the standard enthalpy of formation of NH3 gas? N2(g)+3H2(g)→ 2NH3(g); ΔrH°=-92.4 kJ mol-1 (A) +46.2 KJ mol-1 (B) -46.2 KJ mol-1 (C) -36.5 KJ mol-1 (D) +36.5 KJ mol-1

Tardigrade Admin · Accepted Answer

N2(g)+3H2(g) → 2NH3(g) ; ΔrH°=-92.4 KJ mol-1 ∴ Standard enthalpy of formation of NH3(g) =(-92.4/2) =-46.2 kJ/mol

Q. What is the standard enthalpy of formation of $N H_{3}$ gas?
$N_{2 (g)} + 3 H_{2 (g)} \to 2 N H_{3 (g)}; Δ_{r} H^{\circ} = - 92.4 k J m o l^{- 1}$

$+ 46.2 K J m o l^{- 1}$

$- 46.2 K J m o l^{- 1}$

$- 36.5 K J m o l^{- 1}$

$+ 36.5 K J m o l^{- 1}$

$N_{2 (g)} + 3 H_{2 (g)} \to 2 N H_{3 (g)}; Δ_{r} H^{\circ} = - 92.4 K J m o l^{- 1}$
$∴$ Standard enthalpy of formation of $N H_{3 (g)}$
$= \frac{- 92.4}{2}$
$= - 46.2 k J / m o l$

Q. What is the standard enthalpy of formation of NH3​ gas? N2(g)​+3H2(g)​→2NH3(g)​;Δr​H∘=−92.4kJmol−1

+46.2KJmol−1

−46.2KJmol−1

−36.5KJmol−1

+36.5KJmol−1