### Units of K

Posted:

**Wed Feb 22, 2017 12:15 am**I was somewhat confused on the sign of k.

Since the General Rate equation for RXN aA --> bB is

Rate = -1/a d[A]/dt = 1/b d[B]/dt, and we know d[A]/dt = k[A]^(molecularity)

would the sign of k change whether we are considering the product or reactant? Or is it always positive? Is there something I'm missing here?

Since the General Rate equation for RXN aA --> bB is

Rate = -1/a d[A]/dt = 1/b d[B]/dt, and we know d[A]/dt = k[A]^(molecularity)

would the sign of k change whether we are considering the product or reactant? Or is it always positive? Is there something I'm missing here?