1. In a titration, a 25cm3 sample of nitric acid, HNO3, was used to react with 100cm3 of 0.50 mol/dm3 sodium hydroxide (NaOH) solution. A) Calculate the number of moles of sodium hydroxide used.

B) Calculate how many moles of nitric acid react.

C) Calculate the concentration of nitric acid in mol/dm3.

Asolution is made by dissolving 25.5 grams of glucose (c6h12o6) in 398 grams of water. what is the freezing point depression of the solvent if the freezing point constant is -1.86 °c/m? show all of the work needed to solve this problem.

Hot air balloons float in the air because of the difference in density between cold and hot air. in this problem, you will estimate the minimum temperature the gas inside the balloon needs to be, for it to take off. to do this, use the following variables and make these assumptions: the combined weight of the pilot basket together with that of the balloon fabric and other equipment is w. the volume of the hot air inside the balloon when it is inflated is v. the absolute temperature of the hot air at the bottom of the balloon is th (where th> tc). the absolute temperature of the cold air outside the balloon is tc and its density is ďc. the balloon is open at the bottom, so that the pressure inside and outside the balloon is the same. as always, treat air as an ideal gas. use g for the magnitude of the acceleration due to gravity.

Which change to the system wood cause the freely-moving piston to lower?