posted by Anna on .
Can someone check these homework answers please?
32. The barometric pressure measured outside an airplane at 9 km was 259 mmHg. Calculate the pressure in kPa.
36. A diving bell is a container open at the bottom. As the bell descends, the water level inside changes so that the pressure inside equals the pressure outside. Initially, the volume of the air is 8.58 m^3 at 1.020 atm and 20 degrees C. What is the volume at 1.584 atm and 20 degrees C.
40. A mole of gas at 0 degrees C and 760 mmHg occupies 22.41 L. What is the volume at 20 degrees C and 760 mmHg?
44. A sample of 62.3 cm^3 of argon gas at 18 degrees C was contained at a pressure of 155 kPa in a J-shaped tube with mercury. Later the temperature changed. When the mercury level was adjusted to give the same pressure of argon, the gas volume changed to 50.9 cm^3. What was the final temperature of the argon?
And I need help with this problem.
Methanol can be produced in industrial plants by reacting carbon dioxide with hydrogen in the presence of a catalyst. Water is the other product. how many volums of hydrogen are required for each volume of carbon dioxide when each gas is at the same temperature and pressure?
Is this just a mol mol comparison within the formula? What is is the unbalanced formula?
For #40 I get 24.05 which I would round to 24.0.
For #44 I used (V1/T1) = (V2/T2)
62.3/291 = 50.9/T2 and for T2 I obtained 237.9 which rounds to 238 K.
For the last problem,
CO2 + 3H2 ==>CH3OH + H2O
When everything is present as a gas (I think this is at elevated temperature so H2O will be a gas), you need not go through the mole procedure but you may take a short cut and use volumes directly. Therefore, 3 volumes of H2 are required for each volume of CO2; i.e., 1 liter of CO2 will take 3 liters of H2 (and will produce 1 liter CH3OH and 1 liter of H2O