Solution Manual - General Chemistry 10th edition - Chapter 7 - Exercises - Heat Capacity (Specific Heat) - Number 2 page 283

QUESTION

Calculate the final temperature that results when (a) a 12.6 g  sample of water at absorbs 875 J of heat; (b) a 1.59 kg sample of platinum at gives off 1.05 kcal of heat (sp ht of Pt = 0.032 cal g^-1 °C^-1).




SOLUTION

(a)

m   = 12.6 g

Q   = 875 J

Cp = 4.18 J g^-1 °C^-1

Q   = m Cp dT

dT = Q  /  m . Cp

      = 875 J   /   (12.6 g  .  4.18 J g^-1 °C^-1)

      = 16.6135034556087 °C

(b)

Q   = 1.05 kcal

      = 1050 cal

m   = 1.59 kg

      = 1590 g

Cp = 0.032 cal / g °C

dT = Q   /   m . Cp

      = 1050 cal   /  (1590 g  .  0.032 cal / g °C)

      = 20.6367924528302 °C