Question

Find the unit of the rate constant of a reaction represented with a rate equation, rate = $k[A{]}^{1/2}[B{]}^{3/2}$

• A. $mo{l}^{-1}L{s}^{-1}$
• B. $s^{-1}$
• C. $mol{L}^{-1}{s}^{-1}$
• D. $mo{l}^{-2}{L}^2{s}^{-1}$
• E. $mo{l}^{-3}{L}^3{s}^{-1}$

Answer 1

Answer: (A)

$\because$ Rate $(r)=k$ [concentration] ${}^n$

$\therefore k=\frac{\text{ rate }}{[\text{ concentration }{]}^n}$

or, $k=\frac{\left[mol{L}^{-1}\right]\cdot s^{-1}}{{\left[mol{L}^{-1}\right]}^{\frac{1}{2}}\cdot {\left[mol{L}^{-1}\right]}^{\frac{3}{2}}}$

$k=\frac{\left[mol{L}^{-1}\right]\cdot s^{-1}}{{\left[mol{L}^{-1}\right]}^2}$

$k=mo{l}^{-1}L{s}^{-1}$