Statement (A) : Units of rate of reaction may be expressed as $\mathrm{mol} {\mathrm{L}}^{-1} {\mathrm{S}}^{-1}$

 Statement (B) : In the case of gaseous reaction, rate will have the unit of atm ${\sec }^{-1}$

 Statement (C) : Instantaneous rate is more accurate and may also be defined as equal to average rate when $∆\mathrm{t}\to 0$