NEET Chemistry Chemical Kinetics Questions Solved


87.5% of a radioactive substance disintegrates in 40 minutes. What is the half life of the substance ?

(A) 13.58 min                                                   

(B) 135.8 min

(C) 1358 min                                                    

(D) None of these

(A) Radioactive decay follow first order kinetics Determination K by substituting the respective values.

K=2.303tlogaa-x=2.30340logaa-0.875a=2.30340loga0.125a=2.30340log 8=0.051 min-1t1/2=0.693K=0.6930.051=13.58min.

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