200 mL of 100°C hot tea was poured in a 250 mL vacuum flask and sealed. 0.01 mL of water in the tea was then evaporated in the flask after an hour. Assume no energy is lost to the surroundings and the temperature is kept at 100°C after an hour. Given density of water at 100°C = 0.958 g/mL; specific latent heat of vaporization of water 2260 J/g; R = 0.0821 L-atm/mol-K; molar mass of water = 18.02 mol/g; 0°C = 273.15 K. (a) What is the mass (in mg) of 0.01 mL water at 100°C? (b) How much energy (in J) is required to vaporize 0.01mL of water? (c) How many moles (in mmol, i.e. 10-3 mol) of gases inside the vacuum flask in the beginning? (d) What is the pressure (in atm) inside the flask after an hour? (Hint: Consider the number of mole of water vapor vaporized from 0.01 mL water.)

200 mL of 100°C hot tea was poured in a 250 mL vacuum flask and sealed. 0.01 mL of water in the tea was then evaporated in the flask after an hour. Assume no energy is lost to the surroundings and the temperature is kept at 100°C after an hour. Given density of water at 100°C = 0.958 g/mL; specific latent heat of vaporization of water 2260 J/g; R = 0.0821 L-atm/mol-K; molar mass of water = 18.02 mol/g; 0°C = 273.15 K. (a) What is the mass (in mg) of 0.01 mL water at 100°C? (b) How much energy (in J) is required to vaporize 0.01mL of water? (c) How many moles (in mmol, i.e. 10-3 mol) of gases inside the vacuum flask in the beginning? (d) What is the pressure (in atm) inside the flask after an hour? (Hint: Consider the number of mole of water vapor vaporized from 0.01 mL water.)