Question

The rate constant for zero order reaction is _____________.

[Note : $c_0$ and $c_t$ are concentrations of reactants at respective times].

• A. $k=\frac{c_0}{2t}$
• B. $k=\frac{c_0-c_t}{t}$
• C. $k=ln[\frac{c_0-c_t}{2t}]$
• D. $k=\frac{c_0}{c_t}$

Answer 1

Answer: (B)

$k=\frac{c_0-c_t}{t}$

Given that :

$k\times t=\frac{1}{n-1}[\frac{1}{(a-x{)}^{n-1}}-\frac{1}{a^{n-1}}]$

for $n=0$, we get -

$t\times k=\left(\frac{1}{0-1}\right)\left(\frac{1}{(a-x{)}^{0-1}}\right)$$=-1\left[\right(a-x)-a]$

$k=\frac{a-(a-x)}{t}$ or $\frac{c_0-c_t}{t}$

where,

$a=c_0$ and $(a-x)=c_t$