Saturday

August 30, 2014

August 30, 2014

Posted by **tracy** on Thursday, November 1, 2012 at 10:23am.

a. What is the new volume if 0.600 mole O2 gas is added?

b. Oxygen is released until the volume is 12.0L. How many moles of O2 are removed?

c. What is the volume after 7.50 g He is added to the O2 gas already in the container? plss neeed help

- chem -
**DrBob222**, Thursday, November 1, 2012 at 1:43pma. I would use PV = nRT and solve for P (that gives you initial P). No T is listed but you can use any convenient T. Add mols O2 initially + 0.6 mol O2 and use PV = nRT again to solve for new volume. Use the old P you calculated and don't change T from what you used.

b. Redo PV = nRT with new V = 12.0 L. Solve for n O2 and subtract from total mols O2 to find moles removed.

c. Convert 7.5g He t mols, add to mols O2 available from part b and redo PV = nRT and solve for V.

- chem -
**tracy**, Thursday, November 1, 2012 at 6:10pmin a. I got 60 L for volume and .8 moles(.2+.6moles. now in b. i got .16 mole so where do I subtract .16 from should I subtract it from .8 moles or from the initial mole which is .2 mole

- chem -
**DrBob222**, Friday, November 2, 2012 at 12:40amFrom the 0.8; that's where the volume was 60 L.

By the way there is a shorter way of doing this

Notice that if we use PV = nRT and solve for n = (PV/RT). Since P, R, and T are constant, the n = V; therefore,

(n1/V1) = (n2/V2). As an eample, for part a, (0.2/15) = (0.8/V2) and V2 = 60 which can be done in your head.

For part b, (0.8/60) = (n2/12); n2 = 0.16

**Related Questions**

chemistry - A sample containing 4.8g of O2 gas has a volume of 15.0L. Pressure ...

Chemistry - A sample containing 4.80g of O2 gas has a volume of 15.0L. Pressure ...

chem - A sample containing 7.60 gas has a volume of 31.0 . Pressure and ...

chemistry - 1)A sample of CO2 gas which weighs 0.85 grams has a volume of 1.30 ...

chemistry - A sample containing 4.8 g of O2 gas has a volume of 15.0L. Pressure ...

chemistrty - A sample containing 7.20g O2 gas has a volume of 33.0L Pressure and...

chemistry - When a sample of carbon dioxide gas is at 36 degrees and 105 kpa is ...

physics - A sample of gas at P = 1123 Pa, V = 1.41 L, and T = 291 K is confined ...

CHEMISTRY!! D: - 1. A sample of gas under a pressure of 622 kPa has a volume of...

Chemistry;HELP - 1. A sample of gas under a pressure of 622 kPa has a volume of...