Which type of reaction is 2Cu(NO3)2 2CuO + 4NO2 + O2?
a. Single-replacement
b. Double-replacement
c. Combination
d. Decomposition
[Ques. 2] A car is moving down a freeway in a straight line at a constant rate of 32.0 m/s for 3.0 s. Its acceleration is
a. 9.8 m/s2.
b. 9.8 m/s.
c. zero.
d. 32.0 m/s.
e. 11.0 m/s2.
[Ques. 3] Which type of reaction is 4Al + 3O2 2Al2O3?
a. Decomposition
b. Combination
c. Double-replacement
d. Single-replacement
[Ques. 4] An object with a mass of 5 kg is dropped and takes 9 s to hit the ground. Then another object with a mass of 10 kg is dropped from the same point. How long does it take to hit the ground?
a. 9 s
b. 18 s
c. 5 s
d. 81 s
e. 729 s
[Ques. 5] The coefficients needed to balance the reaction Sb2S3 + HCl SbCl3 + H2S are, respectively,
a. 1, 2, 1, and 1.
b. 2, 1, 3, and 1.
c. 1, 2, 1, and 3.
d. 1, 6, 2, and 3.
e. 1, 1, 1, and 1.
[Ques. 6] An object in free fall has
a. a constant speed.
b. a constant velocity.
c. a velocity that changes 9.8 m/s each second.
d. an acceleration that depends on its mass.
[Ques. 7] When the equation Al + O2 Al2O3 is balanced, the coefficient of Al2O3 is
a. 1
b. 2
c. 3
d. 4
[Ques. 8] A freely falling object
a. has a uniformly increasing velocity.
b. is unaffected by gravity.
c. has a uniformly increasing acceleration.
d. has a uniformly increasing displacement.
[Ques. 9] When the equation Al + O2 Al2O3 is balanced, the coefficient of O2 is
a. 1
b. 2
c. 3
d. 4
[Ques. 10] If the magnitude of the velocity of an object increases, we may be sure that during the time of this increase,
a. the object is accelerated.
b. the acceleration of the object increases.
c. the object is moving in a straight path.
d. the object is changing direction.
e. none of these
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