Question

___________ is the unit for the rate of a chemical reaction.

• A. Mole l${}^{-1}$s
• B. Mole l${}^{-1}$s${}^{-1}$
• C. Mole l s
• D. Mole l${}^{-1}$

Answer 1

The correct option is B Mole l${}^{-1}$s${}^{-1}$

The rate of a chemical reaction is the change in concentration over the change in time and is a metric of the "speed" at which a chemical reactions occurs and can be defined in terms of two observables:

1. The Rate of Disappearance of Reactants: $\frac{[-\Delta Reactants]}{\Delta time}$

2. The Rate of Formation of Products: $\frac{\left[\Delta Products\right]}{\Delta time}$

Thus, the units for the rate is Molarity per Seconds $\left(\frac{M}{s}\right)$. or Moles per litre per second $\left(moles{l}^{-1}{s}^{-1}\right)$.