A 25.0g sample of liquid ammonia, initially at its normal boiling point (−33.3∘C, 1atm), is contained in an insulated metal cylinder. A heating coil supplies thermal energy to the ammonia in identical pulses, each pulse delivering 1.50kJ. The molar enthalpy of vaporization of ammonia is 23.3kJmol−1.
(a) After the first energy pulse, calculate the mass of ammonia that has vaporized.
(b) Determine the minimum number of complete pulses required to vaporize 60.0% of the original sample.
(c) After five pulses have been delivered, compute the mass of ammonia that remains in the liquid phase.