Physics clicker question: temperature change during phase change

Physics 205A, Spring Semester 2009
Cuesta College, San Luis Obispo, CA

Cf. Giambattista/Richardson/Richardson, Physics, 2/e, Multiple-Choice Question 14.8 (extended)

Students were asked the following clicker question (Classroom Performance System, einstruction.com) at the start of their learning cycle:

The change in temperature of a material undergoing a phase change (such as melting/freezing, or boiling/condensing) is typically:
(A) 0.
(B) ∞.
(C) some finite number.
(D) (Not enough information is given.)
(E) (I'm lost, and don't know how to answer this.)

Sections 30880, 30881
(A) : 12 students
(B) : 4 students
(C) : 14 students
(D) : 0 students
(E) : 1 student

This question was asked again after displaying the tallied results with the lack of consensus, with the following results. No comments were made by the instructor, in order to see if students were going to be able to discuss and determine the correct answer among themselves.

Sections 30880, 30881
(A) : 14 students
(B) : 2 students
(C) : 14 students
(D) : 0 students
(E) : 0 students

Correct answer: (A)

Temperatures remain constant during phase changes; thus the change in temperature must be zero.

Pre- to post- peer-interaction gains:
pre-interaction correct =39%
post-interaction correct = 47%
Hake, or normalized gain = 13%