Question

# 1)At 25°C, some second-order reaction 3 X (g)→ 2 Y (g) + Z (g) has a...

1)At 25°C, some second-order reaction 3 X (g)→ 2 Y (g) + Z (g) has a half-life of 5.82 hours when the initial concentration of X is 4.46 M. (a) What is rate constant for this reaction? (b) How much X will be left after 17.5 hours?

Example of answer: (a) k = [type your answer] M–1 h–1; (b) [X]t = [type your answer] M.

2)

For some second-order reaction: 3 X (g)→ Y (g) + Z (g).

The following data were obtained at 400°C:

[A]o = 9.38 x 10-1 M

[A]t = 2.35 x 10-3 M

t = 543 s

Calculate the rate constant for this reaction.

Example of answer: k = [type your answer with correct units].

3)

The activation energy for the following reaction: 2 N2O (g)→ 2 N2 (g) + O2 (g) is 250 kJ/mol.

By what factor (how many times) will the rate constant increase when the temperature is raised from 728°C to 852°C?

Hint: Consider which temperature: lower or higher corresponds bigger rate constant.

Example of answer: = [type your answer]. (k2 > k1)