1. a heart shaped mylar is filled with helium gas. the ballon holds 0.605 moles of gas when the pressure is 1.248 atm and the temperature is 16.1 degrees C. what is the volume of the balloon? 2. a 90.8 g sample of xenon is in a 15.7 L container. what is the pressure of this gas in mmHg 279° C?

3. when 4.85 L of methane (CH4) gas is completely burned with oxygen (O2), it produces water vapor and carbon dioxide. at a temperature of 22° C and a pressure of 135 kPa, what mass of water vapor will result?
CH4 + 2O2 > 2H2O + CO2

How much would the freezing point of water decrease if 4 mol of sugar were added to 1 kg of water(k=1.86 c/mol/kg for water and i=1 for sugar

11. phosphorus-32 is radioactive and has a half life of 14 days. how much of a 124 mg sample of phosphorus-32 is present after 56 days? a) 7.75 mg b) 15.5 mg c) 31.0 mg d) 62.0 mg

Nebulae are enormous clouds in outer space. they are made mostly of hydrogen gas, helium gas, and dust. some nebulae glow brightly, while others do not. the stars that people see are huge, bright balls of glowing gas. they are made mostly of hydrogen and helium. which statement correctly describes other ways in which nebulae and stars are different? a. stars can form inside a nebula but a nebula can never be produced by any star. b. a star always has a higher density than a nebula. c. stars can never form inside a nebula but a nebula can be produced by any star. d. a nebula always has a higher density than a star.