A cylindrical tank of $4$ m diameter was filled with acetone to a depth of $2\mathrm{.}3$ cm from the top for storage and is exposed to ambient temperature of $18\mathrm{.}8$C in a gentle current of air

$1.$ Calculate the fall in level of acetone after $1$ hour

ii$.$ Calculate the loss in rupees, if acetone is worth Rs$.2$ per liter Data: Vapour pressure of acetone at $8^3*$ C $=170$ mm of Hg Barometric pressure $765\mathrm{.}5$ mm of Hg Density of Acetone$-0\mathrm{.}79$ g$/$cc Diffusivity of acetone in air at $18\mathrm{.}8$C$-0\mathrm{.}09$