4790 joules of heat are added to 222 grams of water originally at 27.7 C. What is the final temperature of the water?

2 Answers
Nov 3, 2016

If I am correct, you will need to know the equation Q=mc ΔT to solve this problem.

Explanation:

Here, you are given the values for Q, m and c can be obtained from your textbook. According to mine, the value should be 4.19 J/C.

4790 J= 222g * 4.19 * (x°C-27.7°C)

Note that I let x represent the final temperature. And now, all you have to do is some simple arithmetic and solve for x!

The final answer is 32.8°C

Nov 3, 2016

The final temperature is "32.9"^@"C".

Explanation:

Use the specific heat equation:

![http://pinstopin.com/specific-heat-equation](useruploads.socratic.org)

Known

Q="4790 J"
c_"water"=4.184 "J"/("g·"^@"C")
m="222 g"

T_"initial"="27.7"^@"C"

Unknown

T_"final"

Solution

Rearrange the equation to isolate Delta T.

Q=cmDeltaT

Divide Q by cm.

Delta T=Q/(cm)

Delta T=(4790cancel"J")/((4.184cancel"J")/(cancel"g·"^@"C")xx222cancel"g"="5.16"^@"C"

Now that Delta T is known, we'll write it as equal to the final temperature minus the initial temperature.

Delta T=T_f-T_i

Add T_1 to both sides.

Delta T+T_i=T_f

5.16^@"C"+"27.7"^@"C"="32.9"^@"C"