3.0 moles of N2 gas are placed inside of an empty balloon.  6.0 moles of O2 gas are then placed inside of the same balloon, which has now doubled in volume compared to when it contained only the N2 gas.  The temperature of the balloon has not changed.  Which of these statements is most likely to be true?

75.0 grams of solid sodium hydroxide is dissolved in 1.000 L of 20.0°C water in a coffee cup calorimeter.  What is the final temperature of the water, in °C? Show all work, and highlight your answer in a readable background color. 

An inflated balloon has a volume of 151 L at sea level (1.00 atm), and is allowed to ascend until the pressure is 0.761 atm. During ascent, the temperature of the gas falls from 35°C to -14°C.  What is the volume of the balloon at its final altitude?

A gas-filled balloon has an initial volume of 3.53 L at 2.30 atm and 61°C.  What is the final volume (in L) of the balloon if the pressure and temperature are adjusted to 76.3 kPa and 8°C? Show all work, and highlight your answer in a readable background color.

The combustion of liquid carbon disulfide produces carbon dioxide gas and sulfur dioxide gas.  What volume (in L) of sulfur dioxide gas is produced along with 83.1 kJ of heat under standard thermochemical conditions?  Assume 100% yield. Show all work, using dimensional analysis wherever possible, and highlight your final answer in a readable background color.

[EXTRA CREDIT] (3 pts possible, question will show as being out of 0 pts) Given the following data: Ca(s) +   O2(g)   —>   CaO(s)                            

At a particular temperature and pressure, the effusion rate of HCl gas is 813 particles per minute.  What is the effusion rate of steam at that same temperature and pressure?

Which of the following is most likely to be insoluble in water?

The pressure of a gas sample is measured with a closed-ended manometer containing mercury, as shown in the figure below.  What is the pressure of the gas sample, in torr?

Which statement below best explains why Ernest Rutherford was expecting the alpha particles to pass through the gold foil undeflected?