How many grams of water can be heated from 15.0 oC to 55oC using 4250.0 J.

Answer 1

The specific heat of water is 4.18 J/g •°C, so that means that it takes 4.18 joules of energy to raise one gram of water 1 °C.

Change in temp = 55 - 15 = 40°C

So we can calculate how much energy it would take to raise the temp of one gram of water by one degree using the following

(4.18 J/g•°C) * (40°C) * (1 gram) = 167.2 J

So if it takes 167.2 J of energy to raise on gram of water 40°C, we now we can calculate the amount of grams of water that can heated with 4250 J of energy

(4250 J) ÷ (167.2 J) = 25.42 grams of water can be heated from 15°C to 55°C

Answer 2

q = mC∆T

q = heat = 4250 J

m = mass of water = ?

C = specific heat of water = 4.814 J/g/degree

∆T = change in temperature = 55 - 15 = 40 degrees

Solving for m (mass) we have...

m = q/(C)(∆T) = 4250 J/(4.184 J/g/degree)(40 degrees)

m = 25. 4 g