Chapter 17: Phases and Phase Changes Selected Solutions

Selected Solutions

13. Since the gas is at constant temperature we know that

21. (a) The rms speed of H₂O is more than the rms speed of O₂, since it is less massive but has the same average kinetic energy.

(b) First we use Oxygen to find the temperature:

33. For each rod, the expression for the compressive force is

49. The amount of heat used to raise the temperature of the ice to the melting temperature of 0 ^oC is

The amount of heat available for other processes is

Q₂ = Q_total - Q₁ = 2.6 x 10⁵ J - 1.15 x 10⁴ J = 2.49 x 10⁵ J

The amount of heat needed to melt all the ice is

Q_f = mL_f = (1.1 kg)(33.5 x 10⁴ J/kg) = 3.69 x 10⁵ J

Since Q_f > Q₂, not all of the ice melts, so the final temperature of the water is 0 ^oC.

The mass that melts is:

Therefore, the mass that remains is:

m_ice = 1.1 kg - m_f = 1.1 kg - 0.74 kg = 0.36 kg

53. Let us first assume that T_f = 100 ^oC, then the heat lost by iron is

Selected Solutions by David Reid, Eastern Michigan University. ©2002 by Prentice Hall, Inc.

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