Aflask contains 2.0 mol of he gas at 25°c and 1.00 atm. how much he gas, in grams, must be added to increase the pressure to 2.00 atm at constant temperature and volume?

Harvey kept a balloon with a volume of 348 milliliters at 25.0˚c inside a freezer for a night.  when he took it out, its new volume was 322 milliliters, but its pressure was the same.  if the final temperature of the balloon is the same as the freezer’s, what is the temperature of the freezer? the temperature of the freezer is  kelvins.

If 16.00g of hydrogen gas reacts with 126.73g of oxygen, how many grams of water are yielded? (both reactants are completely consumed in the reaction.)

Liquid from a brewery fermentation contains 10% ethanol and 90% water. part of the fermentation product (50,000 kg/h) is pumped to a distillation column on the factory site. under current operating conditions, a distillate of 45% ethanol and 55% water is produced from the top of the column at a rate of one-tenth that of the feed. what is the composition of the waste "bottoms" from the still?