Mothballs are commonly made of napthalene. The naphthalene

diffuses from the ball into the surrounding air and the

naphthalene gas kills insects and repels animcals. Determine the

flux of naphthalene from a mothball of diameter $0\mathrm{.}75$ inches to

air at $25$oC and $1$ atm that has a relative velocity of $0\mathrm{.}3$ m$/$s$.$ The

diffusivity of naphthalene in air at $45$oC and $1$ atm pressure is

$6\mathrm{.}92$ x $10-6$ m$2/$s$.$ The vapour pressure of naphthalene is $0\mathrm{.}555$

mmHg