Question

Using the following thermochemical equation, calculate how much heat is associated with the decomposition of 4.00 moles of NH4Cl.

NH3(g) + HCl(g) è NH4Cl(s) ΔH = -176 kJ

A) 5000
B) 740
C) 407
D) 704

Answer 1

Answer:

D

Explanation:

$4 \times - 176 = - 704$

Answer 2

Answer:

D - 704

Explanation:

The balanced thermochemical equation relates the energy change to moles, not grams, so we first convert the amount of NH4Ck to moles and then use the thermochemical equation to determine the energy change:

4.00 mole NH4Cl x (-176 ÷ 1 mole NH4Cl)

= -704