How powerful a vacuum do I need to reduce pressure to 1 Torr in a 6" cube?
Q. I have a sealed 6" cube (air, not liquid) and I need to reduce pressure to 1 Torr. Does anyone have suggestions for specific vacuum pumps or recommendations on where I can find this info? Thanks.
Asked by Crlaozwyn - Sun Sep 27 12:06:39 2009 - - 1 Answers - 0 Comments

A. Vacuum pumps are rated in microns, which seems to be a strange system of units. From what I can find, Atmospheric pressure measures around 759,968 microns. Since 1 atm = 760 torr, that means 1 torr = 1000 microns. Most pumps I could find are in the 100 micron range, which is 0.1 torr, so any would do for your application. Size is not a concern, as you have a fixed volume, and no time limitation. the reference has one of hundreds.
Answered by billrussell42 - Tue Sep 29 08:42:49 2009

What is the volume in degrees C and 195 torr?
Q. A sample of gas has a volume of 390 ml when measured at 25 degrees C and 760 torr. What volume in ml will it occupy at 25 degrees C and 195 torr?
Asked by Chuck H - Mon Mar 17 02:00:20 2008 - - 2 Answers - 0 Comments

A. The mathematical form of the Combined Gas Law is: P1 x V1 / T1 = P2 x V2 / T2 When any five of the six quantities in the equation are known, the sixth can be calculated. For your problem: Unit Conversions: P1 = 760.mmHg / 760 mmHg x 1.000 atm = 1.00 atm V1 = 390.mL / 1000.0 mL/L = 0.390 L V2 = P1V1T2/P2T1 = 1.00 atm x 0.390 L x 25. K / (1.95x102 atm x 25. K) = 2.0x10^-3 L
Answered by Farzin - Mon Mar 17 15:32:31 2008

What is the helium pressure, in torr, when flask filled with helium is connected to open-ended manometer?
Q. The open end is exposed to the atmosphere, where prevailing pressure is 752 torr. The mercury level in the open arm is 26 mm above that in the arm connected to the flask of helium.
Asked by Lala - Fri Jun 20 18:36:04 2008 - - 1 Answers - 0 Comments

A. Sphincter tone
Answered by Tanner_Salad - Fri Jun 20 18:43:50 2008

How do you Calculate the partial pressure of sulfur dioxide in torr?
Q. Two gases, hydrogen sulfide (14.0 grams) and sulfur dioxide (15.9 grams), are confined in a container at a pressure of 910 torr
Asked by lilant2012 - Fri Feb 22 13:26:27 2008 - - 1 Answers - 0 Comments

A. Moles H2S = 14.0 / 34 g/mol = 0.412 Moles SO2 = 15.9 / 64 g/mol = 0.248 total moles =0.660 0.248 / 0.660 = p (SO2) / 910 p (SO2) = 341.9 torr
Answered by Dr.A - Fri Feb 22 16:17:51 2008

What is the boiling point of an aqueous solution that has a vapor pressure of 22.5 torr at 25 Celsius?
Q. What is the boiling point of an aqueous solution that has a vapor pressure of 22.5 torr at 25 Celsius? I have no clue on what to do can someone help me please!
Asked by javier s - Sun Jan 18 23:37:40 2009 - - 2 Answers - 0 Comments

A. hey Go here I answered it. But please answer my quesition on the bottom, it is MGC too.
Answered by Pablo - Mon Jan 19 21:26:41 2009

What volume would the gas occupy at the same temperature at 770 torr?
Q. A 37 L tank contains a gas under a pressure of 522 atm. What volume would the gas occupy at the same temperature at 770 torr of pressure? Answer in units of L.
Asked by foofoo8315 - Wed Feb 25 19:25:22 2009 - - 1 Answers - 0 Comments

A. Boyle's Law P1V1 = P2V2 (you need to have the same units for pressure) 522 atm x (760 Torr / 1 atm) = 396720 Torr 396720 Torr x 37L x 770 Torr x ?L ?L = 19063 L
Answered by drbillmacmo - Wed Feb 25 19:38:21 2009

what is the final pressure in torr units?
Q. A 2.0 L sample of o2 gas is initially at STP. the volume is doubled while holding the temperature constant. what is final pressure in torr units? the answer is 380 torr, but i have no idea how to get that.
Asked by Stephie - Wed Mar 11 00:35:54 2009 - - 1 Answers - 0 Comments

A. V1 = 2.0 L V2 = 2 x 2.0 = 4.0 L p1 = 1 arm p2 = ? 2.0 x 1 = 4.0 p p = 0.5 atm 0.5 x 760=380 torr
Answered by Dr.A - Wed Mar 11 03:55:22 2009

When the total pressure of the mixture is 600 torr, what is the partial pressure of the nitrogen?
Q. A sealed container has 1 mole of helium and 2 moles of nitrogen at 30 C. When the total pressure of the mixture is 600 torr, what is the partial pressure of the nitrogen? 1. 100 torr 2. 200 torr 3. 400 torr 4. 600 torr
Asked by jesse - Sat May 30 22:39:21 2009 - - 1 Answers - 0 Comments

A. 2/3rds of the moles in the tank are moles of Nitrogen. Therefore, 2/3rds of the pressure is attributed to Nitrogen. 3
Answered by robe and wizard hat - Sat May 30 22:45:49 2009

What is its volume when the temperature is -15.8 C and its pressure is 524 torr?
Q. A sample of ammonia gas at 65.5 C and 524 torr has a volume of 15.31 L. What is its volume when the temperature is -15.8 C and its pressure is 524 torr?
Asked by Guedo - Sun Aug 16 14:49:05 2009 - - 1 Answers - 0 Comments

A. at constant pressure : V1/T1 = V2/T2 T1 = 65.5 + 273.16=338.66 K T2 = - 15.8 + 273.16=257.36 K 15.31 / 338.66 = V2 / 257.36 V2 = 11.6 L
Answered by Dr.A - Sun Aug 16 15:07:10 2009

A chemist collects 416 mL of nitrogen gas over water at 60 C and 677 torr. What is the volume of the dry gas a?
Q. A chemist collects 416 mL of nitrogen gas over water at 60 C and 677 torr. What is the volume of the dry gas at STP if the vapor pressure of water at 60 C is 149 torr?
Asked by Poodu D - Sat Mar 21 22:32:34 2009 - - 1 Answers - 0 Comments

A. pressure N2 = 677 - 149=528 torr =>> 0.695 atm 0.695 x 0.416 L/ 333 K = 1 atm x V / 273 V =0.237 L => 237 mL
Answered by Dr.A - Sun Mar 22 11:34:09 2009

If the sample is transferred to a 1.05 L flask at the same temp, what will the gas pressure Torr in the flask?
Q. A sample of He gas occupies 535 mL at 988 Torr and 25 degrees Celsius. If the sample is transferred to a 1.05-L flask at the same temp, what will be the gas pressure (Torr) in the flask?
Asked by SNJJ 06 - Fri Dec 11 13:06:03 2009 - - 2 Answers - 0 Comments

A. Use Boyle's Law: P1*V1=P2*V2
Answered by christian - Fri Dec 11 13:15:05 2009

If the total pressure in the flasks is 324 torr after the stopcock is opened, determine the initial pressure o?
Q. the flask apparatus contains 2.00 L of H2 at a pressure of 368 torr and 1.00 L of N2 at an unknown pressure. If the total pressure in the flasks is 324 torr after the stopcock is opened, determine the initial pressure of N2 in the 1.00 L flask.
Asked by Sami Y - Mon Nov 10 17:05:48 2008 - - 1 Answers - 0 Comments

A. [2(368 torr) + 1(x)] / 3 = 324 torr 736 + x = 972 x= 236 torr
Answered by The Machine - Mon Nov 10 17:11:35 2008

What is the density at 569 torr and 57 degrees C?
Q. A gas has a density of 29626 g/L at STP. What is its density at 569 torr and 57 C? Answer in units of g/L.
Asked by Kevin L - Sat Feb 6 03:52:19 2010 - - 1 Answers - 0 Comments

A. Actually, this gas is most likely a non-existent flavor (are you sure you didn't misplace a decimal, more likely it is 2.9626 g/L, in which case the gas is likely Chlorine). UF6 is the gas with the largest molar mass known to science, and its density at STP is 15.7 grams/liter (had it existed as an ideal gas at that point, even though it is solid). I will play along with you, and assume you gave the correct value for STP density of the gas. --- Recall the equation for the mass basis version of the ideal gas law: P*V = m*(R/M)*T where P is pressure, V is volume, m is mass, M is molar mass of the gas flavor, R is the molar gas constant which is independent of gas flavor, and T is the absolute temperature. Solve for m/V, which is the… [cont.]
Answered by gintable - Sat Feb 6 04:26:14 2010

A certain liquid has a vapor pressure of 104 torr at 39 C, and a vapor pressure of 407 torr at 83 C. What is t?
Q. A certain liquid has a vapor pressure of 104 torr at 39 C, and a vapor pressure of 407 torr at 83 C. What is the heat of vaporization of the liquid, in kJ/mol?
Asked by Cindy - Mon Jun 14 12:23:09 2010 - - 1 Answers - 0 Comments

A. I do not think the heat of vaporization could be taken from two pieces of data of vapor pressure provided. According to Antoine s equation at least three pieces of data would be needed to get constants A, B and C. then maybe you could compare with existing data to get to know what known compound has same constants A, B and C. Then you would be able to know the heat of vaporization as a function of Pressure, actually you did not say at what pressure you need the heat of vaporization. Regards
Answered by Joaco G - Mon Jun 14 13:11:11 2010

At 85 C the vaper pressure of A is 566 torr and that B is 250. Caculate the composition of a mixture of A and?
Q. At 85 C the vaper pressure of A is 566 torr and that B is 250. Caculate the composition of a mixture of A and B that boils at 85 C when the presure is 0.60atm. Also Caculate the composition of the vaper mixture. Assume ideal behavior.
Asked by Ema Music - Sun Jul 4 20:52:01 2010 - - 1 Answers - 0 Comments

A. 76
Answered by mr_pawr - Sun Jul 4 20:53:18 2010

The original volume is 125 mL. Find the new volume if the pressure changes from 700 torr to 500 torr, the temp?
Q. The original volume is 125 mL. Find the new volume if the pressure changes from 700 torr to 500 torr, the temperature changes from 52 C to 273 K, and the number of moles changes from 0.267 moles to 0.375 moles.
Asked by Poodu D - Sat Mar 21 22:33:51 2009 - - 1 Answers - 0 Comments

A. use the conservation's law : P.V/T=Constant
Answered by Etienne de Quercy, in God Mode - Wed Mar 25 18:02:05 2009

At what temperature will the volume be 15.50 L if the pressure is 871 torr torr?
Q. Chlorine is widely used to purify municipal water supplies and to treat swimming pool waters. Suppose that the volume of a particular sample of Cl2 gas is 8.40 L at 885 torr and 25C.
Asked by Kelsey - Mon Nov 9 19:37:46 2009 - - 1 Answers - 0 Comments

What volume of H2 could be produced at a temperature of 17 oC and a pressure of 762 torr by the reaction of..?
Q. What volume of H2 could be produced at a temperature of 17 degrees C and a pressure of 762 torr by the reaction of 2.78 g of aluminum with hydrochloric acid? How do I do this?
Asked by spider367 - Fri Jan 16 14:04:49 2009 - - 1 Answers - 0 Comments

A. 2Al + 6HCl ---> 3H2 + 2AlCl3 2.78 g Al/27 = .1 mol Al .1/2 = x/ 3 = .15 mol H2 PV=nRT (762) (x) = (.15) (62.4) (290) 762x = 2714.4 x = 3.56 L
Answered by Dr. Merlin Bach - Fri Jan 16 14:12:37 2009

Where can I buy the seed for the plant salicoynia bigelovii torr?
Q. I dont know the common name but I need to find a place where I can find this seed? Thanks!
Asked by Sergio - Mon Mar 17 18:19:38 2008 - - 1 Answers - 0 Comments

A. Are you looking for Salicoria Bigolovii? Here is a link to a page that has some information about the above. I couldn't find a source for seeds but by looking through this site there may be someone who can answer your question. Sounds like an interesting plant!
Answered by Deb S - Mon Mar 17 18:47:14 2008

What is the boiling point of an aqueous solution that has a vapor pressure of 23.0 torr at 25 C?
Q. The answer has to be in degrees Celsius and we are looking for the TB (change in temperature of the boiling point). I know I have to do something with boiling point elevation equation, but I cannot solve for the molality...The book tells me that the KB for water is 0.512 degrees C/m, but the problem doesn't even say we are dealing with water. Ugh, I am so confused. please help!
Asked by Cynthia K - Sun Sep 13 16:39:26 2009 - - 2 Answers - 0 Comments

A. yes we are dealing with water here. It says that aqueous solution right? Use the calusius clapeyron equation ln(p2/p1)= Hvap/R (1/t1 - 1/t2) You need the Hvap for water which is constant in small temp range. hope this helps. have a great day.
Answered by freedert_myers - Sun Sep 13 16:45:32 2009