Question

The decomposition of SO2Cl2 is first order in SO2Cl2 and has a rate constant of 1.42 x 10-4

s
-1 at a
certain temperature.
a. If the reaction started with 75.6 g of SO2Cl2 dissolved in 1.25 L, what would be the
concentration of SO2Cl2 after 3.00 hours?
b. A student claims that the half life of SO2Cl2 changes as the reaction progresses. Do you agree
or disagree with the students claim? Explain your answer. Note: The experiment was
preformed at a constant temperature.

Answer 1

a. 13.0g/L is the concentration of SO2Cl2 after 3.00h

b. FALSE

Step-by-step explanation:

The first order reaction follows the equation:

ln[SO2Cl2] = -kt + ln[SO2Cl2]₀

Where [] is the concentration after time t, k is rate constant = 1.42x10⁻⁴s⁻¹

[]₀ is initial concentration:

a. []₀ = 75.6g/1.25L = 60.48g/L

t in seconds: 3h * (3600s / 1h) = 10800s

Replacing:

ln[SO2Cl2] = -1.42x10⁻⁴s⁻¹*10800s + ln[60.48g/L]₀

ln[SO2Cl2] = 2.5687

[SO2Cl2] = 13.0g/L is the concentration of SO2Cl2 after 3.00h

b. The rate constant of a reaction remains constant if temeprature remains constant.