Units of Rate of reaction and Speciflc rate of Reaction Chemistry Notes

Units of Rate of reaction and Speciflc rate of Reaction Chemistry Notes

Units of Reaction Rate and Specific Reaction Rate (k) :

→ If unit of concentration is mole/litre and unit of time is second or minute or hour, then Unit of reaction rate = moll L-1s-1
= mol L min-1min-1
= mol L-1 hr-1

Units of Rate of reaction and Speciflc rate of Reaction Chemistry Notes

→ The unit of rate constant can be determined as follows:

aA + bB + cC → Product
Rate of reaction k[A]a [B]b [C]c
= k [concentration]a
[concentration]b [concentration]c
Assuming equal concentrations of A, B and C
= k [concentration]a + b + c …… (1)

Units of Rate of reaction and Speciflc rate of Reaction Chemistry Notes 1
Units of Rate of reaction and Speciflc rate of Reaction Chemistry Notes 2

∴ The unit of second order reaction is L mol-1s-1

Units of Rate Constant for Gaseous Reactions :

Dimension of k= (atm)1-xs-1
= (bar)1-xs-1

Here, x = Order of reaction.
For first order reaction, (x = 1) = (atm)1-1s-1
= s-1
For second order reaction (x = 2) = (atm)1-2s-1
= atm-1s-1
For zero order reaction (x = 0) – (atm)1-0s-1
= atm s-1

Units of Rate of reaction and Speciflc rate of Reaction Chemistry Notes

Chemistry Notes