If the heat of combustion for a specific compound is -1450.0 kJ/mol and its molar mass is 51.97 g/mol, how many grams of this compound must you burn to release 230.80 kJ of heat?

Question

matt101 · Answer

We need to use this equation:

$$q=n \Delta H$$
q = total heat released
n = moles of reactant
ΔH = heat of combustion

However, we're given grams in the questions...but remember the relationship between moles and grams: n = m/MM, where m is the mass and MM is the molar mass. Let's rewrite the equation above:

$$q=\frac{m}{MM} \Delta H$$
Now just plug everything in and solve!