Heat and specific heat practice problems

Chemistry Unit 6. Try each one, then open the worked solution. The Credit Sprint app generates unlimited new versions with fresh numbers.

Problem 1.

How much heat (in joules) is needed to warm 240 g of water from 25 °C to 84 °C? (c = 4.184 J/g·°C)

Show solution

q = mcΔT = (240)(4.184)(59) = 59200 J.

Problem 2.

How much heat (in joules) is needed to warm 240 g of water from 17 °C to 56 °C? (c = 4.184 J/g·°C)

Show solution

q = mcΔT = (240)(4.184)(39) = 39200 J.

Problem 3.

How much heat (in joules) is needed to warm 21 g of water from 30 °C to 51 °C? (c = 4.184 J/g·°C)

Show solution

q = mcΔT = (21)(4.184)(21) = 1850 J.

Problem 4.

How much heat (in joules) is needed to warm 71 g of water from 15 °C to 65 °C? (c = 4.184 J/g·°C)

Show solution

q = mcΔT = (71)(4.184)(50) = 14900 J.

Problem 5.

How much heat (in joules) is needed to warm 224 g of water from 17 °C to 50 °C? (c = 4.184 J/g·°C)

Show solution

q = mcΔT = (224)(4.184)(33) = 30900 J.

Problem 6.

How much heat (in joules) is needed to warm 96 g of water from 26 °C to 80 °C? (c = 4.184 J/g·°C)

Show solution

q = mcΔT = (96)(4.184)(54) = 21700 J.