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2. Classification of reactions used in kinetics.
3. Dependence of the reaction rate on concentration. The basic law of kinet-
ics. The order and molecular nature of the chemical reaction.
4. First-order kinetics equations. The half-transformation period.
5. Dependence of the reaction rate on temperature. The empirical rule
of Van’t Hoff. Activation energy; Arrhenius equation.
7. Catalysis. Enzymatic catalysis. The Michaelis-Menten equation and its
analysis.
Input test-control on the topic «Chemical kinetics».
Homework exercises.
1. The rate of some simple reaction is 0.01 mol/ls. Determine the concentra-
tion of the starting substance after 1 minute from the start of the reaction if
the initial concentration of the reagent was 2 mol/l.
Answer
: 1.4 mol/l
2. Write the expression for the «effective mass» law for the reactions given.
Determine the reaction order and reaction molecularity:
a) N
2
O
5
(g) → N
2
O
3
(g) + O
2
(g)
b) 2H
2
S (g) + SO
2
(g)→ 3S (s) + 2H
2
O (g)
c) I
2
(g) + H
2
(g) → 2HJ (g)
d) Mg (HCO
3
)
2
(s) → H
2
O (g) + CO
2
(g) + MgCO
3
(s)
3.How changes of the rate of synthesis of sulfur oxide (VI) from sulfur oxide
(IV) when the concentration of starting materials is decreased by a factor of
two?
Answer
: it will decrease 8 times.
4. How is changed the rate of chemical reaction when the reaction mixture is
cooled by 30°C, if the temperature coefficient is 3?
Answer
: it decreases
27 times.
5. The half-life of radioactive carbon is 20.5 minutes. Calculate the rate
constant.
Answer
: 0.0338 min
–1.
6. Under storing aspirin tablets, it is established that the decomposition
constant at 20 °C is 5×10
–8
min
–1.
Determine the shelf life of aspirin at 20 °C
(decomposition time 10% of the substance).
Answer
: 4 years.
7. What is the activation energy, if the rate of increase in temperature from
290 to 300 K doubled?
Answer
: 49.9 kJ/mol.
8. The activation energy of the decomposition reaction of hydrogen iodide
2HI
⇄
H
2
+ I
2
in a gas mixture at 800 K is 190 kJ/mol. It decreases to 60 kJ/molin
the presence of platinum. Determine how many times the reaction rate in the
presence of platinum is higher.
Answer
: 3,2×10
8.