DETERMINATION OF % COMPOSITION OF PENNIES USING REDOX AND DOUBLE DISPLACEMENT (PRECIPITATION) REACTIONS
ch1
Student: _______________________________________________________________________________________
1. xxWhich one of the following is a "substance" in the sense of the word as used in your textbook?
A.
B.
C.
D.
E.
air tap water sea water water toothpaste
2. Select the best statement.
A.
B.
C.
D.
E.
Physical changes may be reversed by changing the temperature.
Physical changes alter the composition of the substances involved.
Physical properties are not valid characteristics for identifying a substance.
Physical properties are mostly extensive in nature.
Physical changes are usually accompanied by chemical changes.
3. Select the best statement.
A.
B.
C.
D.
E.
Chemical changes provide the only valid basis for identification of a substance.
Chemical changes are easily reversed by altering the temperature of the system.
Chemical changes always produce substances different from the starting materials.
Chemical changes are associated primarily with extensive properties.
Chemical changes are accompanied by changes in the total mass of the substances involved.
4. Which of the following is a chemical change?
A.
B.
C.
D.
E.
boiling of water melting wax broiling a steak on a grill condensing water vapor into rainfall carving a piece of wood
5. Water vapor is less dense than ice because
A.
B.
C.
D.
E.
molecules in the gas phase are in constant motion. molecules in the gas phase have more potential energy than in solids. molecules in the gas phase have more kinetic energy than in solids. gaseous molecules have less mass. molecules in the gas phase have more space between them than in solids.
6. During the swing of a frictionless pendulum, what energy form(s) remain constant?
A.
B.
C.
D.
E.
kinetic energy only potential energy only both kinetic energy and potential energy kinetic plus potential energy
None of these forms remains constant.
7. The most significant contribution to modern
Student: _______________________________________________________________________________________
1. xxWhich one of the following is a "substance" in the sense of the word as used in your textbook?
A.
B.
C.
D.
E.
air tap water sea water water toothpaste
2. Select the best statement.
A.
B.
C.
D.
E.
Physical changes may be reversed by changing the temperature.
Physical changes alter the composition of the substances involved.
Physical properties are not valid characteristics for identifying a substance.
Physical properties are mostly extensive in nature.
Physical changes are usually accompanied by chemical changes.
3. Select the best statement.
A.
B.
C.
D.
E.
Chemical changes provide the only valid basis for identification of a substance.
Chemical changes are easily reversed by altering the temperature of the system.
Chemical changes always produce substances different from the starting materials.
Chemical changes are associated primarily with extensive properties.
Chemical changes are accompanied by changes in the total mass of the substances involved.
4. Which of the following is a chemical change?
A.
B.
C.
D.
E.
boiling of water melting wax broiling a steak on a grill condensing water vapor into rainfall carving a piece of wood
5. Water vapor is less dense than ice because
A.
B.
C.
D.
E.
molecules in the gas phase are in constant motion. molecules in the gas phase have more potential energy than in solids. molecules in the gas phase have more kinetic energy than in solids. gaseous molecules have less mass. molecules in the gas phase have more space between them than in solids.
6. During the swing of a frictionless pendulum, what energy form(s) remain constant?
A.
B.
C.
D.
E.
kinetic energy only potential energy only both kinetic energy and potential energy kinetic plus potential energy
None of these forms remains constant.
7. The most significant contribution to modern