Question

In acidic solution, sucrose is converted to a mixture of glucose and fructose in pseudo first order reaction. It has been found that the concentration of sucrose decreased from 20 mmol L^-1  to 8 mmol L^-1 in 38 minutes. What is the half-life of the reaction?

Answer 1

Initial concentration = [A]₀ = [sucrose]₀

= 20 mmol L^-1

= 20 x 10^-3 mol L^-1

Final concentration = [A]_t = [sucrose]_t

= 8 mmol L^-1

= 8 x 10^-3 mol L^-3

time = t = 38 min 

Half-life period = t_1/2 = ?

For first order reaction,

∴ Half-life period = t_1/2 = 28.74 min