How many kilojoules are released when you raise the temperature of water from 2 oC to 80oC. You have 15.0 g of water

Answer 1

The specific heat of water is 4.18 J/g•°C which means that it takes 4.18 joules of energy to raise one gram of water by 1°C. For this question energy would be consumed not released because the temperature is being raised.

Temp change = 80 - 2 = 78°C

So in order raise the temp of 1 gram of water 78°C, we need to multiply the specific heat times the temp change.

78°C * 4.18 J/g•°C = 326.04 J

Now we need to determine the amount of energy it will take to raise the temp of 15 grams of water by 78°C

326.04 J * 15 grams = 4890.6 J

Now we just need to convert J to kJ by dividing the above answer by 1000

4890.6/1000 = 4.8906 kJ is needed to heat 15 grams of water from 2°C to 80°C