# The temperature of a sample of water changes from 10° C to 20°C when the sample absorbs 418 joules of heat. What is the mass of the sample?

##### 1 Answer

#### Explanation:

Right from the start, just by inspecting the values given, you can say that the answer will be

Now, here's what that is the case.

As you know, a substance's specific heat tells you how much heat is needed to increase the temperature of

Water has a *specific heat* of approximately

Now, how much heat would be required to increase the temperature of

Well, you'd need **another** **another**

#"4.18 J" xx 10 = "41.8 J"#

to increase the temperature of

Now look at the value given to you. If you need **times as much heat** to increase its temperature by

#"1 g" xx 10 = "10 g"#

And that's your answer.

Mathematically, you can calculate this by using the equation

#color(blue)(q = m * c * DeltaT)" "# , where

*final temperature* minus *initial temperature*

Plug in your values to get

#418 color(red)(cancel(color(black)("J"))) = m * 4.18color(red)(cancel(color(black)("J")))/("g" color(red)(cancel(color(black)(""^@"C")))) * (20 - 10)color(red)(cancel(color(black)(""^@"C")))#

#m = 418/(4.18 * 10) = "10 g"#