# How does specific heat of metal compare to that of water?

Aug 31, 2014

Let's start off by defining specific heat. So specific heat is the amount of heat required to raise the temperature of a unit mass of a substance by one degree (typically, Celsius). Basically all this is saying is that, if you had something, and you wanted to raise its temperature to a certain amount, how much energy would you need to actually do that based on the mass of that thing? The formula for specific heat then comes:

Q=cm$\Delta$T
with
c=specific heat (joule/gram degree Celsius)
m=mass (gram)
$\Delta$T=change in temperature (

We can deduce that substances with a high specific heat require a lot of heat to have their temperature raised by one degree. On the other hand, substances with a low specific heat require a smaller amount of heat. This makes sense looking at the equation (if you raise c, Q will increase as well).

Back to the original question, let's think about the properties of water and metal. How much energy would it require to raise the temperature of each?

Imagine we had an equal mass of metal and water being exposed to the same amount of heat. Which one would heat up first? The metal! Think about a hot summer day in which you touch water or a metal rod. Typically, the metal rod would be much hotter than the water.

So, the conclusion could be made that the specific heat of metal is lower than the specific heat of water. It requires less heat per unit mass to create a greater change in temperature for metal than it does for water. This is general of course, since there are different types of metal. If we use an example though, you'd find that:

Specific heat of water: 4.186J/Gram Degree Celsius
Specific heat of, say, iron: 0.444 J/Gram Degree Celsius (iron has a lower specific heat than water)