Question

The reaction A(aq) ---> B(aq) + C(aq) is a first order reaction. The half-life of A(aq) is 86.6 s at 25.0^oC and its half-life is 66.2 s at 45.0^oC. What is its half-life (in s) at 65.0^oC?

Answer 1

Answer:-

This question is solved by using the simple concept of Arrhenius equation which involves the relationship rate constant and the activation energy.

The answer is given in the image,

Answersa Alacgy Beq) +C64) First order reaction K = 0.693 - ttg kr 30-693 86.5 = 8.00 X10-352 kg=0.693 66.2 = 0.0105 52 Ti = 25% = 254273 - 298k T2 2 45°C -45+273 = 318k Inke - ta ( 7 Ino.o105 = Ea , ) 0.26891 = Ea x 20 8.314x298X318 Ea = 10 593-3 1/mol. Now again 73-65° 365+273=338K Ka 8.314 T2 T3. dn K3 =10593.3 tot i 0.010s 8-314 318 338) ankar =0.2371 o-olos K₂ - 0.2371 0.010s = Dolo5 3. = 1.268 K2= 0.01335-1 tha=0.693 = 0.693 K3 0.0133 t1/2 = 52.1 S Half life will be = 52.15.