Integrated Physics and Chemistry TEKS Correlations
(8) Science concepts. The student knows that changes in matter affect everyday
life. The student is expected to:
(C)investigate and identify the law of conservation of mass;
CH4 + O2
66.
Which of the following sets of coefficients balances this equation for the combustion of methane gas?
A.
B.
C.
D.
67.
CO2 + H2O
1,1,1,1
1,2,1,2
2,1,2,1
2,2,3,3
A student placed a piece of steel wool inside a test tube and heated the test tube and its contents over a
Bunsen burner flame for 3 minutes. The student repeated this procedure two more times and collected the
following data.
Data from Steel Wool Investigation
Before Heating
Trial 1
Trial 2
Trial 3
Test Tube
20.0 g
19.4 g
19.5 g
Steel Wool
3.1 g
2.2 g
3.5 g
After Heating
Trial 1
Trial 2
Trial 3
Test Tube
20.0 g
19.4 g
19.5 g
Steel Wool
5.0 g
3.5 g
5.6 g
Which of the following most likely explains why the steel wool gained mass?
A.
B.
C.
D.
The student’s measurements lacked precision.
The steel wool became denser with heating.
The student needed to perform more trials.
The steel wool reacted with oxygen.
Charles A. Dana Center
Science TEKS Toolkit
www.sciencetekstoolkit.org
68.
Students are studying the reaction of copper (II) sulfate and iron. They are going to place an iron nail into a
beaker containing a copper (II) sulfate solution. Before placing the nail into the beaker, the students find the
mass of the nail and of the beaker with the solution in it. They then place the nail in the copper (II) sulfate
solution, and within minutes the solution begins to change color, and small pieces of a copper-colored
substance appear. After the reaction, the mass of the nail plus the beaker and solution will most likely be 
A.
B.
C.
D.
one-quarter of the original mass
half of the original mass
equal to the original mass
double the original mass
Charles A. Dana Center
Science TEKS Toolkit
www.sciencetekstoolkit.org