Question

Based on experimental data, plotting ln[SO2Cl2] vs time fits a straight line with the formula

y= -0.000910t-1.70

What is the concentration of SO2Cl2 after 255 seconds?

Answer 1

Since, the plot is between ln[SO₂Cl₂] vs Time;
therefore it is a first order integrated rate law reaction.

For a first order reaction,

ln[A]_t - ln[A]₀ = -kt

where [A]_t is the concentration at time = t seconds
and   [A]₀ is the concentration at time = 0 seconds

y=-0.000910t - 1.70

Comparing the equation with y = mx + c
Slope = -k = 0.000910

Now at t=0 seconds
ln[SO₂Cl₂] = -1.70
Concentration [SO₂Cl₂] = 0.182M (e^-1.70)

At t = 255 seconds
ln[SO₂Cl₂] = -0.000910 x 255 - 1.70 = -1.932

Concentration of SO₂Cl₂ = 0.144M (e^-1.932)