# How do you calculate the mass of ethanol that must be burnt to increase the temperature of #210 g# of water by #65^@#, if exactly half of the heat released by this combustion is lost to the surroundings?

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The heat of combustion of ethanol is #1367 kJmol^-1# .

The heat of combustion of ethanol is

##### 1 Answer

#### Answer:

You must burn 3.8 g of ethanol.

#### Explanation:

**Step 1. Calculate the theoretical amount of heat required**

The formula for the quantity of heat

#color(blue)(bar(ul(|color(white)(a/a)q = mC_text(s)ΔTcolor(white)(a/a)|)))" "#

where

In this problem,

**Step 2. Calculate the actual amount of heat required**

**Step 3. Calculate the moles of ethanol required**

The equation for the combustion of ethanol is

**Step 4. Calculate the mass of ethanol**