In: Chemistry
Suppose a chemical reaction is first order and has a half-life of 2.5 hr at 100 ºC. Which of the following statements is false regarding this reaction if the temperature is changed?
Question 5 options:
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Sol.
For a first order reaction ,
Rate constant = k = 0.693 / t1/2 ( equation 1 )
where t1/2 is half - life
Also , Arrhenius equation is :
ln ( k2 / k1 ) = ( Ea / R ) × ( T2 - T1 ) / ( T2 × T1 )
( equation 2 )
where k2 and k1 are rate constants at temperatures T2 and T1 respectively
Ea is activation energy and R is gas constant
So , with the help of equations 1 and 2 , we can calculate half - lifes at different temperatures
But the value of activation energy , Ea is not provided in the question . So , it is impossible to calculate half - lifes at different temperatures without Ea value .
Therefore , answer is (D) , Not enough information has been provided in order to make a conclusion