Integrated Rate Laws and Mechanisms: Quiz
Seven questions on integrated rate laws, straight-line plots, half-lives and rate-determining steps, with explanations.
Integrated Rate Laws and Mechanisms: Quiz
7 questions
ln[A] = ln[A]₀ − kt has the form y = c + mx, with slope −k.
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Answer: ln[A] against t
ln[A] = ln[A]₀ − kt has the form y = c + mx, with slope −k.
60.0 min is 3 half-lives: (½)³ = 1/8.
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Answer: 1/8
60.0 min is 3 half-lives: (½)³ = 1/8.
t½ = 1/(k[A]₀) = 1/(0.100 M⁻¹ s⁻¹ × 0.500 M) = 20.0 s.
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Answer: 20.0 s
t½ = 1/(k[A]₀) = 1/(0.100 M⁻¹ s⁻¹ × 0.500 M) = 20.0 s.
For second order, the slope of 1/[A] against t equals +k, with units M⁻¹ s⁻¹.
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Answer: 0.0250 M⁻¹ s⁻¹
For second order, the slope of 1/[A] against t equals +k, with units M⁻¹ s⁻¹.
The slow step sets the rate, and it involves two NO₂ molecules.
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Answer: rate = k[NO₂]²
The slow step sets the rate, and it involves two NO₂ molecules.
It is made in step 1 and used up in step 2, so it does not appear in the overall equation.
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Answer: an intermediate
It is made in step 1 and used up in step 2, so it does not appear in the overall equation.
Doubling half-lives are the signature of second order (t½ = 1/k[A]₀). First order gives constant half-lives; zero order gives shrinking ones.
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Answer: second
Doubling half-lives are the signature of second order (t½ = 1/k[A]₀). First order gives constant half-lives; zero order gives shrinking ones.