A welder using a tank of volume 0.0750 m3 fills it with oxygen 1molar mass 32.0 g>mol2 at a gauge pressure of 3.00 * 105 Pa and temperature of 37.0C. The tank has a small leak, and in time some of the oxygen leaks out. On a day when the temperature is 22.0C, the gauge pressure of the oxygen in the tank is 1.80 * 105 Pa. Find (a) the initial mass of oxygen and (b) the mass of oxygen that has leaked out.

7. using your knowledge of colligative properties explain whether sodium chloride or calcium chloride would be a more effective substance to melt the ice on a slick sidewalk. use 3 – 4 sentences in your explanation. 8. when a 2.5 mol of sugar (c12h22o11) are added to a certain amount of water the boiling point is raised by 1 celsius degree. if 2.5 mol of aluminum nitrate is added to the same amount of water, by how much will the boiling point be changed? show all calculations leading to your answer or use 3 – 4 sentences to explain your answer. 9. if 5.40 kcal of heat is added to 1.00 kg of water at 100⁰c, how much steam at 100⁰c is produced? show all calculations leading to an answer. 10. the freezing of water at 0⁰c can be represented as follows: h2o (l) ↔ h2o(s) the density of liquid water is 1.00 g/cm3. the density of ice is 0.92 g/cm3. in 3 – 4 sentences explain why applying pressure causes ice to melt.

What is the value of keq for the reaction expressed in scientific notation?

If a solution had a ph of 7 what is the solution