Question 21 : For a reaction: 2H₂+2NO —–> 2H₂0 + N₂ the rate law is R =K [H₂][NO]² The Order of the reaction is?
1. None
2. 1
3. 3
4. 2
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Question 22 : The slow rate of a particular chemical reaction might be attributed to which of the following?
1. a low activation energy
2. a high activation energy
3. the presence of a catalyst
4. the temperature is high
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Question 23 : The minimum additional energy, above the average internal energy, which the. reacting molecules must possess so that their collision result in a reaction is known as?
1. Activation energy
2. Average kinetic energy.
3. Threshold energy .
4. None of these
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Question 24 : The specific rate constant, k, for radioactive beryllium–11 is 0.049 s– What mass of a 0.500 mg sample of beryllium-11 remains after 28 seconds?
1. 0.125 mg
2. 0.250 mg
3. 0.0625 mg
4. 0.375 mg
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Question 25 : Determine the molar concentration of A after 140 seconds have elapsed.
1. 0.5
2. 0.3
3. 0.36
4. 0.2
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Question 26 : The activation energy (Ea), in kJ/mole, is:
1. 8.314
2. 27
3. 183
4. 24
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Question 27 : The rate law (or rate equation) is:
1. R = k[ClO₂][OH^-]₂
2. R = k[ClO₂]₂[OH^-]₂
3. R = k[ClO₂][OH^-]
4. R = k[ClO₂]₂[OH^-]
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Question 28 : The catalyst in the above mechanism is:
1. O₃
2. O
3. NO
4. NO₂
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Question 29 : The intermediate in the above mechanism is:
1. NO
2. O₃
3. NO₂
4. O
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Question 30 : If the catalyst in question 42 is added to the reactants, the value of the rate constant, k, would be:
1. larger than that of the uncatalyzed reaction
2. the same as that of the uncatalyzed reaction
3. smaller than that of the uncatalyzed reaction
4. impossible to determine
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