chemistry aqa a level calorimetry question

A vessel and its contents of total heat capacity 120 J K–1 were heated using a methane burner. Calculate the maximum theoretical temperature rise when 0.10 g of methane was completely burned. The standard enthalpy of combustion of methane is
–890 kJ mol–1.

answer

moles methane = = 6.25 × 10–3 (1)
kJ evolved = 6.25 × 10–3 × 890 = 5.56 (1)
5.56 × 103 joules = (mc)T (1)
T = = 46.4 K (1)

I'm completely confused, could someone explain this to me? Thank you.

Reply 1

Hellllpppp

Moles is mass/Mr you need to work this out so you can work out energy from the enthalpy change.
Energy can be found using both enthalpy x moles and mass x specific heat capacity x change in temperature.
You use the first equation to work out the energy in this case as you don’t have all the information for the second.
You then rearrange energy = mass x heat capacity x change in temperature to find temperature change.
Not sure what the mass would be here though so I can’t explain the last two marks, is this the whole question?