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)?
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
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
#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.