Ohio Graduation Test for Science – March 2007
Annotated Item 9
Standard and Benchmark Assessed:
Standard:
Benchmark:
Physical Sciences
C. Describe the identifiable physical properties of substances (e.g., color,
hardness, conductivity, density, concentration and ductility). Explain how
changes in these properties can occur without changing the chemical nature of
the substance.
Multiple Choice Question:
Use the information to answer questions 8 and 9.
Lemonade
On a humid summer day, Franklin put six ice cubes into each of two cups and then poured the
same amount of lemonade into each cup. Cup A was made of plastic, and Cup B was made of
glass. He left the cups for about 20 minutes and then came back. He found a small puddle of
water around Cup A and a larger puddle around Cup B. Franklin determined that the cups were
not leaking.
GS0037PSCXC0331B
9. Suppose Franklin had a third cup, made of Styrofoam®, to which he added the same
number of ice cubes and the same amount of lemonade. What would Franklin expect to
observe after 20 minutes?
A.
B.
C.
D.
The Styrofoam cup would have a smaller puddle than either the glass or plastic cup.
The Styrofoam cup would have a larger puddle than either the glass or plastic cup.
The Styrofoam cup would have a puddle exactly the same size as the plastic cup.
The Styrofoam cup would have a larger puddle than the plastic cup but a smaller puddle
than the glass cup.
Source: Ohio Department of Education
August 07
Ohio Graduation Test for Science – March 2007
Annotated Item 9
Commentary:
This multiple choice question asks students to predict the relative size of a puddle of water
(condensation) produced by a cup made of Styrofoam compared to a plastic cup and a glass
cup. Students must understand that the puddles of water are formed by air condensing on the
cups due to the lower temperature of the cup compared to the surrounding air. Students should
conclude that the lower the temperature of the cup, the more condensation will occur, creating a
larger puddle of water. Therefore, the cup with the lower temperature will have the larger puddle
of water. Students are told that the experiment involved the same amount of liquid and ice in all
three cups and should deduce that the only possible reason for the difference in the
temperature of the cups is the conductivity of the materials from which the cups are made.
Student must recall that Styrofoam is a better insulator than either glass or plastic. Answer
choice A is correct because the Styrofoam cup, the best insulator, will produce the smallest
puddle of water. Answer choices B, C, and D are incorrect since Styrofoam is a better insulator
than glass and plastic, the puddle around the Styrofoam cup will not be larger than or the same
size as the puddles around either the glass or plastic cup.
This question is classified as Communicating Understanding / Analyzing Science Information
because the task requires students to understand that the puddle of water is caused by a
difference in temperature of the cups compared to the surrounding air temperature and to make
the connection that temperature difference is caused by the different properties of the materials
from which the cups are made.
Performance Data:
The percent of public school students selecting answer choice A for question 9 on the March
2007 Ohio Graduation Test was 89%.
Keywords:
insulator, conductor, property, thermal energy
Source: Ohio Department of Education
August 07