Mass.gov
Massachusetts Department of Elementary and Secondary Education
Go to Selected Program Area
Massachusetts State Seal
News School/District Profiles School/District Administration Educator Services Assessment/Accountability Family & Community  
 Student Assessment  Accountability, Partnership, & Assistance  Compliance/Monitoring >  
>
>
>
 
 
 
 
 
 
 
 
 
 
>
>
>
>
>
>
>

Massachusetts Comprehensive Assessment System

2011, High School Chemistry

  Question 11: Open-Response  
Antifreeze is mixed with water in a car’s radiator to help keep the solution from freezing. The graph below shows how the freezing point of a solution of antifreeze and water changes based on the percent of antifreeze in the solution.
The graph has Freezing Point of Solution in degrees Celsius on the x-axis and Percent of Antifreeze in Solution on the y-axis. The scale on the x-axis is 0 degrees Celsius at the top and a negative 80 degrees Celsius at the bottom. The scale on the y-axis is 0 percent antifreeze on the left and 100 percent antifreeze on the right. The curve starts at 0 degrees Celsius and 0 percent antifreeze; the next data point is negative 4 degrees Celsius and 10 percent antifreeze; the next data point is negative 10 degrees Celsius and 20 percent antifreeze; the next data point is negative 18 degrees Celsius and 30 percent antifreeze; the next data point is negative 28 degrees Celsius and 40 percent antifreeze; the next data point is negative 39 degrees Celsius and 50 percent antifreeze; the next data point is negative 55 degrees Celsius and 60 percent antifreeze; the next data point is negative 74 degrees Celsius and 65 percent antifreeze; the next data point is negative 62 degrees Celsius and 70 percent antifreeze; the next data point is negative 45 degrees Celsius and 80 percent antifreeze; the next data point is negative 27 degrees Celsius and 90 percent antifreeze; and the last data point is negative 13 degrees Celsius and 100 percent antifreeze. The shape of the curve is essentially V-shaped.
  1. Based on the graph, estimate the percent of antifreeze in a solution of antifreeze and water that has the lowest freezing point.
  2. Compare the freezing point of 1 L of 40% antifreeze solution with the freezing point of 10 L of 40% antifreeze solution. Explain the reasoning for your answer.
  3. A car mechanic stated that a 50% antifreeze solution provides better protection for the radiator of a car than a 90% antifreeze solution. Is the mechanic’s statement correct or incorrect? Include data from the graph to support your answer.

Scoring Guide and Sample Student Work
Select a score point in the table below to view the sample student response.

ScoreDescription
4 The response demonstrates a thorough understanding of the properties of solutions and pure solvents. The response correctly estimates the percent of antifreeze that has the lowest freezing point. The response correctly compares the freezing point of a 1 L solution of 40% antifreeze with a 10 L solution of 40% antifreeze and explains the reasoning for the answer. The response identifies the mechanic’s statement as correct and includes data from the graph to support the answer.
4
3
The response demonstrates a general understanding of the properties of solutions and pure solvents.
2
The response demonstrates a limited understanding of the properties of solutions and pure solvents.
1
The response demonstrates a minimal understanding of the properties of solutions and pure solvents.
0
The response is incorrect or contains some correct work that is irrelevant to the skill or concept being measured.

Note: There are 2 sample student responses for Score Point 4.

High School Chemistry

Question 11: Solutions, Equilibrium, and Acid-Base Theory
Question 23: Atomic Structure and Periodicity
Question 33: Atomic Structure and Periodicity
Question 44: Properties of Matter and Thermochemistry
Question 45: Bonding and Reactions

Return to the MCAS 2011 Student Work Directory



Last Updated: March 01, 2015
E-mail this page| Print View| Print Pdf  
Massachusetts Department of Elementary and Secondary Education Search · Site Index · Policies · Site Info · Contact ESE