# How to calculate a temperature change when the released heat of a process ist only partly absorbed by the medium?

Hi, I am able to do this question without the "80% of the heat released was absorbed by the water" part, and ended up getting 892.2g

How, does "80% of the heat released was absorbed by the water" affect the answer?

EDIT: I used the formula ((change in)$H)/n = (-mC$(change in)$T$)/$n$ to find the molar heat of combustion of ethanol. I got the mass of the water to be 892.2g.

Is it because molar heat is defined as the heat energy released by one mole of a substance undergoing combustion, and if only 80% released was absorbed, then I just multiply my answer by 0.8?

An explanation would be greatly appreciated, thankyou!

• Could you show your work? How much of the heat from ethanol combustion did you assume went into the water when you got your answer of 892.2g? – Curt F. Mar 8 '15 at 5:04
• I made some edits – chemistryyo Mar 8 '15 at 5:13