Thread: Raising the temperature?

I am reading that kilo calorie is the energy required to raise the temperature of 1 litre of water by 1 %

This begs a question for me, ...from what temperature?

Is it the case that it requires the same amount of energy to raise the temperature of water from say 10 degrees to 11 as it does from 90 to 91?

I presume that pressure has something to do with this too?

And what about other elements and compounds? Is it always the case that to incrementally increase the heat of a substance is always achieved by a proportionate increase in energy? In other words is this a 45% straight line graph?

Zero

Originally Posted by ZeroZero

I am reading that kilo calorie is the energy required to raise the temperature of 1 litre of water by 1 %

This begs a question for me, ...from what temperature?

Is it the case that it requires the same amount of energy to raise the temperature of water from say 10 degrees to 11 as it does from 90 to 91?

I presume that pressure has something to do with this too?

And what about other elements and compounds? Is it always the case that to incrementally increase the heat of a substance is always achieved by a proportionate increase in energy? In other words is this a 45% straight line graph?

Zero

http://en.wikipedia.org/wiki/Heat_capacity

Originally Posted by ZeroZero

I am reading that kilo calorie is the energy required to raise the temperature of 1 litre of water by 1 %

This begs a question for me, ...from what temperature?

Is it the case that it requires the same amount of energy to raise the temperature of water from say 10 degrees to 11 as it does from 90 to 91?

Almost. There is a slight variation, which is why there are actually a number of different "calories":

There is the Thermochemical calorie which is set to be equal to 4.184 joules
The 4° calorie is the energy to raise a gram of water from 3.5°C to 4.5°C which is equal to 4.204 joules
The 15° calorie is from 14.5° to 15.5° and is 4.1855 joules
The 20° calorie is from 19.5° to 20.5° and is equal to 4.182 joules
and the mean calorie is 1/100 the energy needed to raise the temp from 0° to 100°. It is equal to 4.190 joules.

I presume that pressure has something to do with this too?

All the above are at standard pressure.

And what about other elements and compounds? Is it always the case that to incrementally increase the heat of a substance is always achieved by a proportionate increase in energy? In other words is this a 45% straight line graph?

Zero

All substances will show some variation over temp.

cheers