Chem Lab C

[arvind_r]

Let's start adding math/obscure concepts.
To start out simple:
A 1L flask at 400 K and 1 atm pressure of hydrogen gas is sealed to an identical empty flask so that the hydrogen can be distrubuted throughout both flasks. Then, the flasks are heated such that the temperature of the gas inside is 600K. What is the final pressure of hygrogen inside the flasks?

[slowpoke]

lol (Click to Show Hidden Text)

0.75 atm

[arvind_r]

lol (Click to Show Hidden Text)

0.75 atm

Correct, your turn

[kenniky]

No replies for a while, so I'll just ask something lol

A 10.00 mL container of water is at 10.0◦C. A 2.23 g piece of zinc at 121 ◦C is dropped into the container. What is the resultant temperature of the system? (cZn=0.384 J/g◦C)

[Avogadro]

I guess I'll answer that.

Doesn't seem too bad (Click to Show Hidden Text)

12.2 °C

[kenniky]

I guess I'll answer that.

Doesn't seem too bad (Click to Show Hidden Text)

12.2 °C

correct, you can ask a question now

[Avogadro]

Alrighty, here's one.

5 mole samples of CO2, H2O(vapor), Ne, and CH4 are placed in separate, identical 10L cylinders at 25 °C.
a. What pressure, in mm Hg, would be generated? Assume near-ideal behavior.
b. If all of the samples were to be combined into one 20 L container, what pressure would that container be?
c. Holes are punctured in the ends of each of the identical cylinders so as to allow each of the gases to diffuse. From least to greatest, list the relative amount of time that it would take each gas to diffuse.

[kenniky]

Alrighty, here's one.

5 mole samples of CO2, H2O(vapor), Ne, and CH4 are placed in separate, identical 10L cylinders at 25 °C.
a. What pressure, in mm Hg, would be generated? Assume near-ideal behavior.
b. If all of the samples were to be combined into one 20 L container, what pressure would that container be?
c. Holes are punctured in the ends of each of the identical cylinders so as to allow each of the gases to diffuse. From least to greatest, list the relative amount of time that it would take each gas to diffuse.

Answer (Click to Show Hidden Text)

a. PV = nRT
P * 10L = 5 mol * 0.08206 atm L/mol K * 298 K
=> P = 12.227 atm = [b]9292 mmHg
[/b]
b. total: 20 mols
do the same thing
P =[b] 24.45 atm = 18580 mmHg[/b]

c. MM CO2 = 44, MM H2O = 18, MM Ne = 20, MM CH4 = 16
Fastest - CH4 - H2O - Ne - CO2 - Slowest

[Avogadro]

Alrighty, here's one.

5 mole samples of CO2, H2O(vapor), Ne, and CH4 are placed in separate, identical 10L cylinders at 25 °C.
a. What pressure, in mm Hg, would be generated? Assume near-ideal behavior.
b. If all of the samples were to be combined into one 20 L container, what pressure would that container be?
c. Holes are punctured in the ends of each of the identical cylinders so as to allow each of the gases to diffuse. From least to greatest, list the relative amount of time that it would take each gas to diffuse.

Answer (Click to Show Hidden Text)

a. PV = nRT
P * 10L = 5 mol * 0.08206 atm L/mol K * 298 K
=> P = 12.227 atm = [b]9292 mmHg
[/b]
b. total: 20 mols
do the same thing
P =[b] 24.45 atm = 18580 mmHg[/b]

c. MM CO2 = 44, MM H2O = 18, MM Ne = 20, MM CH4 = 16
Fastest - CH4 - H2O - Ne - CO2 - Slowest

Yup! Your turn.

[kenniky]

15g of CaCl2 is added to 100 mL of water. What is the resultant boiling point of the water? (assume standard conditions)