How much heat is released when `850 kg` of ammonia is produced according to the following thermochemical equation?
`N_(2) (g) + 3 H_(2) (g) rarr 2 NH_(3) (g)`, `Delta_(1) H^(@) = -91.8 kJ`
Strategy : To do the calculation, we must convert grams of `NH_(3)` to moles of `NH_(3)`, and then to kilojoules of heat.
Grams of `NH_(3) rarr ` Moles of `NH_(3) rarr` Kilojoules of heat

Explanation

Step 1: Calculating moles of `NH_(3)`
`n_(NH_(3)) = ("Mass"_(NH_(3)))/("Molar mass"_(NH_(3))`
` = (850 xx 10^(3) g)/(17 g NH_(3) mol^(-1))`
`5 xx 10^(4) mol`
Step 2: 2 mol `NH_(3)` formation releases `91.8 kJ`. This, the formation of `5 xx 10^(4) mol NH_(3)` will release
`(91.8 Kj)/(2 mol) xx 5 xx 10^(4) mol = 2.30 xx 10^(6) kJ`