Question

A chemical reaction that is first order in X is observed to have a rate constant of 1.7 x 10–2s–1. If the initial concentration of X is 1.0 M, what is the concentration of X after 190 s?

Answer 1

Answer:

After 190 s the concentration of X will be 0.0396 M

Explanation:

$ln\frac{A_t}{A_0} = -kt$

Where;

Xt is the concentration of X at a time t

X₀ is the initial concentration of X

k is rate constant = 1.7×10⁻² s⁻¹

t is time = 190s

ln(Xt/X₀) = -( 1.7×10⁻²)t

ln(Xt/1.0) =  -( 1.7×10⁻²)190

ln(Xt/1.0) = -3.23

$\frac{X_t}{1} = e^{-3.23}$

Xt = 0.0396 M

Therefore, after 190 s the concentration of X will be 0.0396 M