You might have noticed that if you are trying to boil a lot of water it takes longer than if you only wish to boil a small amount of water.
This is all because of something called ‘heat capacity’. Keep watching to learn more.
Before we get into the details, it is important to realise that there is a difference between ‘heat’ and ‘temperature’.
Temperature is a way of describing how hot or cold an object is and is measured in °C
Whereas heat is a form of energy and is measured in Joules (J).
The more heat energy transferred to an object, the more its temperature will rise. So heat and temperature are related but are not the same.
So what is heat capacity?
The heat capacity of a substance is defined as the amount of heat required to raise the temperature of a material by 1°C.
However, what’s more useful for us to think about is the specific heat capacity of a substance. This is, as it says in the name, a little more specific. It is the amount of heat required to raise 1 kilogram of a material by 1°C.
Different materials have different known specific heat capacities, but we aren’t always given a table like this so, we need to know how to calculate specific heat capacities ourselves.
We have this equation, which can be written as symbols like this.
The energy transferred is the heat energy absorbed or released. This equation can also be rearranged.
To work out, the temperature change, subtract the old temperature from a new temperature. Let’s have a look at the problem. Pause the video and attempt to calculate the specific heat capacity of lead.
How did you get on? The energy transferred is this. The mass is this and the temperature change 10 degrees Celsius because it’s this, take away this.Using the rearranged equations substitute in the values and we get a hundred and twenty-eight joules per kilogram Celsius.
Here is another practice problem, pause the video and attempt to calculate the energy transferred to the LED. did you get it right? We could divide it by 1000 to turn the answer into kilojoules. Notice that the answer is negative this time, it’s because we called the LED the temperature change will always be negative if it is being cooled and positive is it being heated.
So there you have it.
To summarise, specific heat capacity is the amount of energy needed to raise one kilogram of a substance by one degree Celsius.It’s helpful because it allows us to work out how much energy we need to heat up or cool down the substance to decide the temperature. To calculate use the following equation.
Please like and share our videos with your friends, if you have any question that you want help with, just comment below.
SUBSCRIBE to the FuseSchool YouTube channel for many more educational videos. Our teachers and animators come together to make fun & easy-to-understand videos in Chemistry, Biology, Physics, Maths & ICT.
VISIT us at www.fuseschool.org, where all of our videos are carefully organised into topics and specific orders, and to see what else we have on offer. Comment, like and share with other learners. You can both ask and answer questions, and teachers will get back to you.
These videos can be used in a flipped classroom model or as a revision aid.
Find all of our Chemistry videos here:
https://www.youtube.com/watch?v=cRnpKjHpFyg&list=PLW0gavSzhMlReKGMVfUt6YuNQsO0bqSMV
Find all of our Biology videos here:
https://www.youtube.com/watch?v=tjkHzEVcyrE&list=PLW0gavSzhMlQYSpKryVcEr3ERup5SxHl0
Find all of our Maths videos here:
https://www.youtube.com/watch?v=hJq_cdz_L00&list=PLW0gavSzhMlTyWKCgW1616v3fIywogoZQ
Twitter: https://twitter.com/fuseSchool
Access a deeper Learning Experience in the FuseSchool platform and app: www.fuseschool.org
Follow us: http://www.youtube.com/fuseschool
Friend us: http://www.facebook.com/fuseschool
This Open Educational Resource is free of charge, under a Creative Commons License: Attribution-NonCommercial CC BY-NC ( View License Deed: http://creativecommons.org/licenses/by-nc/4.0/ ). You are allowed to download the video for nonprofit, educational use. If you would like to modify the video, please contact us: info@fuseschool.org