Chemical Kinetics

4.3 The order of the reaction is sum of the powers of concentration of reactants in the rate law. According to this,

The order of the reaction = 1/2 + 2

= 2 1/2 or 2.5

The order of the reaction is 2.5

4.2 Given-

Initial concentration (A₁) = 0.5M

Final concentration (A₂) = 0.4M

Time = 10 mins.

The formula for average rate of the reaction is,

r_av = -1/2 X Δ{A} / Δt → Equation 1

? {A} = (A₂)-( A₁), the equation 1 is written as,

r_av = -1/2 X A₂ - A₁ / Δt

= -1/2 X 0.4-0.5 / 10

= -1/2 X 0.1 / 10

= 0.005 mol L^-1 min^-1

= 5 * 10^-3 mol L^-1 min^-1

The average rate of the reaction is 5 * 10^-3 mol L^-1 min^-1

4.1 Given-

Initial concentration (R₁) = 0.03M

Final concentration (R₂) = 0.02M

Time = 25 mins.

The formula for average rate of the reaction is,

r_av = - Δ{R} / Δt → Equation 1

? {R} = (R₂)-( R₁), the equation 1 is written as,

r_av = - R₂ - R₁ / Δt

= -0.02-0.03 / 25

= 4 X 10^-4 mol L^-1 min^-1

The average rate of reaction in seconds is given by,

= 4 X 10^-4 mol L^-1 / 60 S

(dividing by 60 to convert minutes to seconds)

= 6.6 * 10^-6 mol L^-1 s^-1

The average rate of the reaction in minutes is 4 * 10^-4 mol L^-1 min^-1 and in seconds is 6.6 * 10^-6 mol L^-1 s^-1