Question

Assertion : In a second-order reaction with respect to A, when you double [A], the rate is quadrupled.
Reason : The rate equation is $r={k\left[A\right]}^2$ for such a reaction.

• A. Both Assertion and Reason are true and Reason is the correct explanation of Assertion
• B. Both Assertion and Reason are true but Reason is not the correct explanation of Assertion
  
• C. Assertion is true but Reason is false
  
• D. Assertion is false but Reason is true
  
• E. Both Assertion and Reason are false
  

Answer 1

Answer: (A)

Both Assertion and Reason are true and Reason is the correct explanation of Assertion

Rate equation is as follows:
$OlderRate=k[A{]}^2$ equation -1
This shows that reaction is $2nd$ order.
So if we double the concentration of the A , then new reaction rate can be written as follows:
$NewRate=k[2A{]}^2$
$NewRate=k\times 4[A{]}^2$
$NewRate=4k[A{]}^2$ equation -2
Now, comparing equation -1 and 2 we get :
New Rate = $4\times OlderRate$