# A calorimeter contains 15 grams of water. The water's temperature increases by 10 C°. How much heat energy was added to the water? (Hint: water's specific heat is 1 cal/g°C)?

##### 1 Answer

#### Explanation:

Unsurprisingly, the key to this problem is the hint.

The thing to remember about a substance's **specific heat** is that it tells you the amount of energy needed in order increase the temperature of

Now, water is said to have a specific heat of

The thing to remember here is that you need **for every** **of water** and **for every** **in temperature**.

So, you have

#15 color(red)(cancel(color(black)("g"))) * "1 cal"/(1color(red)(cancel(color(black)("g"))) * 1^@"C") = "15 cal" ""^@"C"^(-1)#

This tells you that **for every** **increase** in the temperature of the sample,

#10color(red)(cancel(color(black)(""^@"C"))) * overbrace("15 cal"/(1color(red)(cancel(color(black)(""^@"C")))))^(color(blue)("for 15 g of water")) = color(darkgreen)(ul(color(black)("150 cal")))#

I'll leave the answer rounded to two **sig ifgs**, but keep in mind that you only have one significant figure for the increase in temperature.