For a reaction ${1 \over 2}A \to 2B$ rate of disappearance of ‘A’ is related to the rate of appearance of ‘B’ by the
expression
$ - {{d[A]} \over {dt}}$ = ${1 \over 2}{{d[B]} \over {dt}}$
$ - {{d[A]} \over {dt}}$ = ${1 \over 4}{{d[B]} \over {dt}}$
$ - {{d[A]} \over {dt}}$ = ${{d[B]} \over {dt}}$
$ - {{d[A]} \over {dt}}$ = $4{{d[B]} \over {dt}}$
