SCHA031
Assignment 1
2023
1. The rate constant for the first-order decomposition of a compound A in the
reaction 3 A →P is kr = 2.65 × 10−7 s −1 at 25°C.
(a) What is the half-life of A?
(5)
(b) What will be the pressure, initially 45.0 kPa at 60 s after initiation of the
reaction?
(3)
2. A reaction 3 A → P has a seventh-order rate law. Write the rate law
expression and derive an equation for the time required for the concentration
of A to change into P.
(6)
3. Calculate the pressure (in Pa) of argon gas required to produce a collision rate
of 4.5 × 1020 s−1 at 425 K on a circular surface of diameter 1.95 mm.
(6)
[20 Marks]