Molar enthelpy of combustion of magnesium

[domthebomb]

1. Homework Statement
In a calorimeter, a 1.0g sample of magnesium is burned to form MgO. In doing so, 25.5 kJ of energy is released. The molar enthalpy of combustion of magnesium is:

a) -0.0392 kJ/mol
b) -25.5 kL/mol
c) -306.2 kJ/mol
d) -620 kJ/mol

Homework Equations

Q= mc DELTA t

The Attempt at a Solution

2Mg + O2 --> 2MgO

... don't know where to start


PLEASE! i need help fast

 

[Borek]

If 1g of magnesium releases 25.5 kJ of energy when burnt, how much energy will be released when 1 mole will be burnt?