Chemical Changes and Structure
Rates of Reaction NAT 5
Homework One
1. A student made the following statements about chemical reactions.
A
B
C
D
A solid is always formed
A gas is always produced
There is always a colour change
A new substance is always formed
Identify the statement which is true for all chemical reactions.
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2.
Which of the following would not be evidence of a chemical reaction when the
solid is added to the solution?
A. A colour change
B. A gas being given off
C. The temperature rising
D. The solid disappearing
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3. Which of the following is not an example of a chemical reaction?
A. Ice melting
B. Iron rusting
C. Methane burning
D. Neutralising an acid
4.
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Which of the following pairs of reactants would produce hydrogen the
most slowly?
A. Magnesium powder and 4 mol l-1 acid
B. Magnesium ribbon and 2 mol l-1 acid
C. Magnesium powder and 2 mol l-1 acid
D. Magnesium ribbon and 4 mol l-1 acid
(1)
5. In an exothermic reaction
A. There is no energy change
B. Energy is released to the surroundings
C. Energy is absorbed from the surroundings
D. The energy of the products is greater than the energy of the reactants
6.
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A reaction is endothermic if
A. Energy is required to start the reaction
B. Heat is released during the reaction
C. The temperature drops during the reaction
D. The temperature rises during the reaction
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Question 7 and 8 refer to the following diagram. A student carried out several
experiments with metals and acids.
7. Identify the two experiments which should be compared to show the effect
of particle size on the speed of reaction
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8. Using collision theory, explain why experiment C would have a faster rate of
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reaction than experiment F.
9.
A
B
Exothermic
Addition
C
D
Precipitation
Endothermic
Identify the type of chemical reaction represented by the following reaction.
Ba2+(OH-)2(aq)
+
(H+)2SO42-(aq)
Ba2+SO42-(s)
+
2H20(l)
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Question 10 and 11 refer to the following diagram. Two students investigated
the reaction between magnesium and dilute hydrochloric acid.
10. Identify the two experiments which could be compared to show the effect
of concentration on the speed of reaction.
(1)
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11.
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Identify the experiment with the fastest speed of reaction.
12. When calcium chloride is dissolved in water, heat is released to the
surroundings.
a) What term is used to describe chemical reactions which give out heat?
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b) What does the term ‘endothermic’ mean?
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Question 13 and 14 refer to the following diagram. A student set up four
experiments to investigate the solubility of aspirin.
13. Identify the two experiments which could be compared to show the effect
of concentration on the speed of reaction.
(1)
14. Identify the experiment with the fastest rate of reaction.
(1)