Sunday

April 20, 2014

April 20, 2014

Number of results: 920

**AP Chemistry**

Three gases, xenon, helium, and hydrogen are confined in a 10.0 L vessel at a pressure of 7.0 atm. Intially the vessel contains 3.0 moles of xenon, 2.0 moles of helium, and 2.0 moles of hydrogen. What would the partial pressure of helium be if 5.0 moles of hydrogen are added ...
*Wednesday, April 6, 2011 at 12:49pm by Paxton*

**chemistry**

A 6.0 L flask contains a mixture of methane, argon and helium at 45 degrees C and 1.75 am. If the mole fractions of helium and argon are 0.25 and 0.35, respectively, how many molecules of methane are present?
*Tuesday, March 1, 2011 at 8:23pm by Katie*

**Chem**

A balloon contains 30.0 L of helium gas at 103 kPa. What is the volume of the helium when the balloon rises to an altitude where the pressure is only 25.0 kPa? Assume that the temperature remains constant
*Wednesday, January 19, 2011 at 2:30pm by Shrell*

**Chem**

A balloon contains 30.0 L of helium gas at 103 kPa. What is the volume of the helium when the balloon rises to an altitude where the pressure is only 25.0 kPa? Assume that the temperature remains constant
*Wednesday, January 19, 2011 at 2:30pm by Shrell*

**Chem**

A balloon contains 30.0 L of helium gas at 103 kPa. What is the volume of the helium when the balloon rises to an altitude where the pressure is only 25.0 kPa? Assume that the temperature remains constant
*Wednesday, January 19, 2011 at 2:30pm by Shrell*

**physics**

A rigid tank contains 38:0 kg of O2 gas at a pressure of 9:70 atm. If the oxygen is replaced by helium, how many kilogram of helium will be needed to produce a pressure of 8:00 atm?
*Monday, May 20, 2013 at 12:43pm by miya*

**Chemistry**

A 10.0 L tank holds helium gas at 82 C and 1.70 atm. What mass of helium gas is in the tank?
*Monday, January 24, 2011 at 8:58pm by Hunter *

**Chemistry**

A 10.0 L tank holds helium gas at 82 C and 1.70 atm. What mass of helium gas is in the tank?
*Monday, January 24, 2011 at 9:01pm by Hunter *

**Chemistry**

A 10.0 L tank holds helium gas at 82 C and 1.70 atm. What mass of helium gas is in the tank?
*Monday, January 24, 2011 at 9:02pm by Hunter *

**Chemistry**

A 10.0 L tank holds helium gas at 82 C and 1.70 atm. What mass of helium gas is in the tank?
*Monday, January 24, 2011 at 9:05pm by Hunter *

**chemistry**

what colour does helium burn? what colour is helium in the spectra? thanks :)
*Saturday, May 29, 2010 at 10:48am by suzie*

**chemistry hw please help**

I have no clue how to figure this problem out.. The Goodyear blimps, which frequently fly over sporting events, hold approximately 1.90×105 ft^3 of helium. If the gas is at 24 degrees Celsius and 1.0 atm, what mass of helium is in the blimp?
*Tuesday, November 10, 2009 at 3:42pm by mike*

**Physics**

A clown at a birthday party has brought along a helium cylinder, with which he intends to fill balloons. When full, each balloon contains 0.036 m3 of helium at an absolute pressure of 1.2 x 10^5 Pa. The cylinder contains helium at an absolute pressure of 1.6 x 10^7 Pa and has ...
*Sunday, April 15, 2007 at 1:18am by Mary*

**science**

What volume of helium would be in a balloon the size of a soft drink bottle? What's the volume of the small drink bottle? That's how much helium would be there. no the question was WHAT WAS THE VOLUME OF HELIUM WOULD BE IN A BALLOON THE SIZE OF A SOFT DRINK BOTTLE? no the ...
*Wednesday, January 31, 2007 at 5:42pm by smart monkey girl96*

**Physics**

You seem to be describing an inelastic collision in which the helium and hydrogen atoms stick together to form a helium hydride molecule. If so, use the law of conservation of momentum. Apparently your teacher or text book writer is unaware that there is no such thing as an ...
*Thursday, January 31, 2013 at 1:27am by drwls*

**chemistry**

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles)of He(g) is present in a helium-oxygen mixture having a density of 0.538g/L at 25celsius and 721mmHg ?
*Friday, September 26, 2008 at 8:17pm by tomi*

**Chemistry**

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of is present in a helium-oxygen mixture having a density of 0.498 at 25 and 721 ?
*Sunday, October 7, 2012 at 6:09pm by Ayesha*

**college chemistry**

A sample of helium occupies 1521 mL at 719 mmHg. Assume that the temperature is held constant and determine a) the volume of the helium at mmHg. b)the pressure, in mmHg, if the volume is changed to 315mL
*Tuesday, October 23, 2012 at 11:10pm by Haley*

**science**

how would 10 grams of helium be different that 10 grams of helium in a sealed container.
*Monday, December 9, 2013 at 7:28pm by jaylon*

**Physics plzzzzzzzzz help**

so ? A Goodyear blimp typically contains 4770 m3 of helium (He) at an absolute pressure of 1.10 x 105 Pa. The temperature of the helium is 274 K. What is the mass (in kg) of the helium in the blimp? This is just a case of applying the ideal gas law, n = PV/RT. You know the ...
*Friday, December 1, 2006 at 1:57am by maysam*

**physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to move off at an angle =45. The neutron's initial speed is 3.8×105 .
*Monday, March 29, 2010 at 8:35pm by Anonymous*

**Chemistry**

a cylinder of helium has a volume of 8.0 L. The pressure of the gas is 388 lb in -2 at 25*C. What volume will the helium occupy at a standard atmospheric pressure (14.7 lb in -2) assuming there is no temperature change?
*Friday, November 11, 2011 at 6:41pm by Mindy*

**Physics**

Air is vibrating in a tube (closed at both ends) at its fundamental frequency of 160 Hz. If the tube is filled with helium instead, what is its fundamental frequency? Use 1020 m/s for the speed of sound in helium.
*Wednesday, January 30, 2013 at 11:24am by Scott*

**Physics**

Air is vibrating in a tube (closed at both ends) at its fundamental frequency of 160 Hz. If the tube is filled with helium instead, what is its fundamental frequency? Use 1020 m/s for the speed of sound in helium.
*Thursday, January 31, 2013 at 5:11pm by lindsey*

**Science**

Helium gas in a balloon occupies 2.5 L at 300.0 K. The balloon is dipped into liquid nitrogen that is at a temperature of 80.0 k. What will the volume of the helium in the balloon at the lower temperature be? I got a weird answer like .66667 and i used charles law
*Saturday, February 12, 2011 at 3:42pm by Lauren*

**chemistry**

Helium-oxygen mixtures are used by divers to avoid the bends and are used in medicine to treat some respiratory ailments. What percent (by moles) of He is present in a helium-oxygen mixture having a density of 0.528g/L at 25 degree celsius and 721 mmHg ?
*Saturday, May 4, 2013 at 7:39pm by molly*

**math**

A study to determine whether or not a football filled with helium traveled farther when kicked than one filled with air found that while the football filled with helium went, on average, farther than the one filled with air, the difference was not statistically significant. ...
*Sunday, October 7, 2007 at 5:23pm by Devon*

**Chem **

The blimp is filled with a gas less dense than air; i.e., usually helium. Hydrogen is even less dense than helium but there is a fire hazard with hydrogen. Read about the Hindenburg disaster if you want to follow up on that.
*Sunday, June 6, 2010 at 8:57pm by DrBob222*

**Chemistry**

A helium baloon has a volume of 28.9L, what is the mass of helium inside the ballon? what is the mass of the same volume of air it displaces? MM of air = 29.0g/mol, 25C (temperature) and 1 atm.
*Wednesday, November 17, 2010 at 10:13am by Ashley*

**Physics**

A container having a volume of 1 m3 holds 90 mol of helium gas at 176 ◦ C. Boltzmann’s constant is 1.38 × 10 −23 J/K. Assuming the helium behaves like an ideal gas, what is the average kinetic energy per molecule? Answer in units of J
*Sunday, February 10, 2013 at 5:44pm by Conor*

**Chemistry**

In a certain experiment a sample of Helium in a vacuum system was compressed at 25 degrees C from a volume of 200.0 mL to a volume of 0.240 mL where its pressure was found to be 30.0 mm Hg. What was the orginal pressure of the Helium?
*Thursday, February 14, 2008 at 12:56am by britt*

**chemistry**

A weather balloon if it starts with 10 liters of helium at 0km elevation and a temperature of 20 degrees. it is released and rises up through the atmosphere to an elevation of 12km where the temperature is -60degrees. calculate the volume of the helium at 12km.
*Sunday, June 3, 2012 at 9:26pm by Cynthia*

**chemistry **

A large cylinder of helium had a small hole through which the helium escaped ata rate of 0.0064 mol/hr. How long would it take for 0.010 mol of CO to leak through a similar hole if it were at the same pressure?
*Saturday, May 1, 2010 at 6:18pm by Amy *

**chemistry**

the diameter of a helium atom is about 1*10^2pm.suppose that we could line up helium atoms side by side in contact with one another. aproximately how maney atoms would it take to make the distance from end to end 1cm ?
*Friday, September 7, 2012 at 5:04pm by whitney*

**Science Question 2**

The helium flash converts three helium nuclei to what heavier element? A.beryllium B.boron C.lithium D.carbon E.iron Carbon. Carbon has six protons, obtained from three helium nuclei. http://abyss.uoregon.edu/~js/ast122/lectures/lec16.html A
*Monday, December 11, 2006 at 10:07pm by Liz*

**Chem**

Please tell me if these are right? A mixture of oxygen and helium is prepared for a scuba diver that will descend to 125 feet below the ocean surface. At that depth the diver breathes a gas mixture that has a total pressure of 8atm. If the particle pressure of the oxygen in ...
*Monday, November 29, 2010 at 1:29pm by Lindsay*

**science **

The diameter of a neutral helium atom is about 128 pm. Suppose we could lin up helium atoms side by side in contact with one anohter. Approximately how many atoms would it take to make the distance 1 cm from end to end.
*Thursday, September 2, 2010 at 7:45am by paulie*

**Chemistry**

Each of 2 front tires in the car is filled with a different gas. One tire contains 116 g of helium, another tire has 160 g of unknown gas. How many times heavier is a molecule of the unknown gas than an atom of helium?
*Saturday, November 10, 2012 at 8:59am by Christina*

**chem**

3. Each of 2 front tires in the car is filled with a different gas. One tire contains 116 g of helium, another tire has 160 g of unknown gas. How many times heavier is a molecule of the unknown gas than an atom of helium?
*Saturday, April 13, 2013 at 10:48am by Anonymous*

**chemistry**

a 10.0L ballon contains helium gas at a pressure of 655mmHg, what is the new pressure, in mmHg, of the helium gas at 20.0L, if no change in temp or amount of gas
*Thursday, March 1, 2012 at 2:03pm by shaun*

**Chemistry**

a sample of helium gas has a volume of 1.25L at -125celcius and 50.0atm. the gas is compressed at 50.0 atm to volume of 325ml. what is the final temperature of the helium gas in Celcius
*Monday, April 8, 2013 at 8:37pm by Mckee*

**chemistry**

assume the diameer of a neutral helium atom is 1.40 x 10 to the second power pm. suppose that we could line up helium atoms side by side in contact with one another. how many atoms would it take to make the distance from end to end 9.00cm
*Monday, February 21, 2011 at 11:46pm by Anonymous*

**chemistry**

If helium added to the mixture increases the pressure to 1.90 {\rm atm}, what is the partial pressure ({\rm atm}) of the helium?
*Thursday, November 18, 2010 at 10:25pm by Anonymous*

**Earth Space Science**

The appearance of fixed lines in this spectrum was successfully explained .... Electrons, like other particles, have properties of both a particle and a wave. ... a type of three-dimensional standing wave—a wave form that does not move ..... of the helium from gas wells, as ...
*Tuesday, May 4, 2010 at 6:15pm by Anonymous*

**chemistry**

The diving atmosphere used by the U.S. Navy in its undersea Sea-Lab experiments consisted of 0.036 mole fraction O2 and 0.058 mole fraction N2, with helium (He) making up the remainder. What are the masses of nitrogen, oxygen, and helium in a 7.22-g sample of this atmosphere?
*Monday, December 20, 2010 at 9:37am by Nagaa*

**Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to move off at an angle of 45 degrees. The neutron's initial speed is 5.9×105 m/s. Determine the speeds of the two particles ...
*Friday, October 8, 2010 at 6:43pm by Bartholomew*

**CHEM**

A cylinder with a movable piston contains 2.00g of helium, He, at room temperature. More helium was added to the cylinder and the volume was adjusted so that the gas pressure remained the same. How many grams of helium were added to the cylinder if the volume was changed from ...
*Sunday, October 28, 2007 at 11:23pm by K*

**Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle θ'2 = 44° from the neutron's initial direction. The neutron's initial speed is 7.0 105 m/s. ...
*Sunday, March 7, 2010 at 10:04pm by Ben*

**Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle θ'2 = 44° from the neutron's initial direction. The neutron's initial speed is 7.0 105 m/s. ...
*Sunday, March 7, 2010 at 10:04pm by Ben*

**CHEMISTRY**

IN A CERTAIN EXPERIEMT A SAMPLE OF HELIUM IN A VACUUM SYSTEM WAS COMPRESSED AT 25C FROM A VOLUME OF 6000.0ML TO A VOLUME OF 240.0ML WHERE ITS PRESSURE WAS FOUND TO BE 32.0 MM HG. WAHT IS THE ORIGINAL PRESSURE OF HELIUM? (P1V1)/T1 (P2V2)/T2 Change T to Kelvin.
*Monday, January 8, 2007 at 10:15pm by TIFFANY*

**Chemistry**

Fill a balloon with helium gas to a volume of 2.68 L at 23 celsius and 789mmHg. What would the volume of helium if the pressure changes to 632 mmHg but the temperature is unchanged. This is how I solved it V2 = V1 X P1/P2 2.68L X 23/789 = V2 =.078 L Is this correct
*Sunday, October 21, 2007 at 7:07pm by lt*

**Chemistry **

Assume the diameter of a neutral helium atom is 1.40 x 10^(2)pm. Suppose that we could line up the helium atoms side by side in contact with one another. How many atoms would it take to make the distance 5.80 cm from end to end? How do I solve this, and what is the correct ...
*Saturday, September 8, 2012 at 2:09pm by Cassidy *

**Physics**

Helium balloons are used regularly in scientific research. A typical balloon would reach an altitude of 40.0 km with an air density of 4.3*10^-3 kg/m^3. At this altitude the helium in the balloon would expand to 540000.0m^3. Find the buoyant force on the balloon.
*Tuesday, December 24, 2013 at 11:07am by Hil*

**Chemistry**

Fill a balloon with helium gas to a volume of 2.68 L at 23 celsius and 789mmHg. What would the volume of helium if the pressure changes to 632 mmHg but the temperature is unchanged. This is how I solved it V2 = V1 X P1/P2 2.68L X 789/632 = ANSWER V2 =.3.35 L Is this correct
*Tuesday, October 23, 2007 at 12:06am by LT*

**Chemistry**

Hi I was reading that in a many electron atom (eg. Helium), it is assumed that each electron occupies its own orbital.. thus,the overall wavefunction (w) is w(1).w(2)... how is this possible?? isn't the 1s orbital of helium filled with 2 electrons so what do they mean that ...
*Sunday, December 7, 2008 at 6:24pm by Kimora*

**college**

A gas containing both hydrogen molecules (each molecule contains two hydrogen atoms) and helium atoms has a temperature of 300 K. How does the average speed of the hydrogen molecules compare to the helium atoms?
*Friday, October 25, 2013 at 3:50pm by Anonymous*

**Chemistry**

You need to choose an atom. Helium is the easiest which has protons, neutrons and electrons. I presume you are looking for a Bohr/Rutherford Model ((Broken Link Removed) Thus for helium you will need a nucleus of 2 protons and 2 neutrons around which there is a circle ...
*Wednesday, November 30, 2011 at 2:34am by Dr Russ*

**Chem 151**

The atmosphere in a sealed diving bell contained oxygen and helium. If the gas mixture has 0.200 atm of oxygen and a total pressure of 3.00 atm, calculate the mass of helium in 10.0 L of the gas mixture at 40 degrees Celsius.
*Thursday, March 21, 2013 at 9:50pm by Double checking ans*

**General Physics**

A neutron collides elastically with a helium nucleus (at rest initially) whose mass is four times that of the neutron. The helium nucleus is observed to rebound at an angle è'2 = 45° from the neutron's initial direction. The neutron's initial speed is 6.6x10^5 m/s. Determine ...
*Thursday, October 30, 2008 at 3:47pm by Scott*

**physics**

An ionized helium atom has a mass of 6.6*10^-27kg and a speed of 4.4*10^5 m/s. The atom moves perpendicular to a 0.75-T magnetic field on a circular path of radius 0.012m. Determine whether the charge of the ionized helium atom is +e or +2e. Can anyone please give me some ...
*Tuesday, April 1, 2008 at 2:52pm by Kelly*

**physics**

The GoodYear blimp is kept aloft by helium gas which fills a volume of 4559m^3. It can carry a maximum load of 1176kg. How much more mass could the blimp carry if it were filled with hydrogen? Take the density of helium gas to be 0.160kg/m^3 and that of hydrogen to be 0.081kg/m^3
*Wednesday, April 10, 2013 at 11:08am by Anna*

**Chemistry**

Consider a sample of helium and a sample of neon, both at 30ºC and 1.5atm. Both samples have a volume of 5.0 liters. Which statement concerning these samples is not true? a- each weighs the same amount b- each has the same # of atoms of gas c- the density of the neon is ...
*Friday, November 6, 2009 at 4:36pm by John S.*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.7 kg m-3. Under these conditions the total surface area of the balloon is 0.52 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 4:18am by Anonymous*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.5 kg m-3. Under these conditions the total surface area of the balloon is 0.72 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 8:44am by student*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.5 kg m-3. Under these conditions the total surface area of the balloon is 0.72 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 8:57am by student*

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.7 kg m-3. Under these conditions the total surface area of the balloon is 0.52 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 1:04am by .*

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.3 kg m-3. Under these conditions the total surface area of the balloon is 0.33 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Sunday, December 16, 2012 at 12:13pm by T*

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.3 kg m-3. Under these conditions the total surface area of the balloon is 0.33 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Sunday, December 16, 2012 at 11:27pm by Please Help Me!!!!!!!!*

**Physics**

A balloon has a volume of 1000 m3 and a mass of 500 kg when empty. When full of helium, what is the maximum mass it can lift off the ground? The density of helium is 0.18 kg/m3 and the density of air is 1.29kg/m3.
*Thursday, July 25, 2013 at 9:31pm by Trent Joseph*

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.31 kg m-3. Under these conditions the total surface area of the balloon is 0.11 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 1:04am by Odesa*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.35 kg m-3. Under these conditions the total surface area of the balloon is 0.57 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 7:31am by lena*

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.31 kg m-3. Under these conditions the total surface area of the balloon is 0.11 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 9:26am by Paul*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.35 kg m-3. Under these conditions the total surface area of the balloon is 0.57 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 12:27pm by timur*

**chimistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.82 kg m-3. Under these conditions the total surface area of the balloon is 0.39 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 1:23pm by School girl*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.35 kg m-3. Under these conditions the total surface area of the balloon is 0.57 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 1:29pm by student*

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.79 kg m-3. Under these conditions the total surface area of the balloon is 0.47 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 3:46pm by anonymous*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.86 kg m-3. Under these conditions the total surface area of the balloon is 0.56 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 11:47pm by kkr*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.35 kg m-3. Under these conditions the total surface area of the balloon is 0.57 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 4:54am by anita*

**Problem**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.92 kg m-3. Under these conditions the total surface area of the balloon is 0.26 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 7:26am by asd*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.92 kg m-3. Under these conditions the total surface area of the balloon is 0.26 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 2:28pm by asd*

**Chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.35 kg m-3. Under these conditions the total surface area of the balloon is 0.88 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 3:10pm by JoeBob*

**Physics**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.35 kg m-3. Under these conditions the total surface area of the balloon is 0.88 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 3:11pm by JoeBob*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.66 kg m-3. Under these conditions the total surface area of the balloon is 0.88 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Sunday, December 16, 2012 at 6:01am by meshy*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.42 kg m-3. Under these conditions the total surface area of the balloon is 0.46 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Friday, December 14, 2012 at 1:29pm by anonymous*

**science**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.23 kg m-3. Under these conditions the total surface area of the balloon is 0.46 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Sunday, December 16, 2012 at 11:46am by fatine*

**physics**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.72 kg m-3. Under these conditions the total surface area of the balloon is 0.17 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Sunday, December 16, 2012 at 11:08pm by Anonymous*

**physics**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.72 kg m-3. Under these conditions the total surface area of the balloon is 0.17 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Sunday, December 16, 2012 at 11:08pm by Anonymous*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.55 kg m-3. Under these conditions the total surface area of the balloon is 0.78 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Monday, December 17, 2012 at 7:18am by hk*

**astronomy**

Supernovas produce and eject carbon and heavier elements, in a violent explosion. The remainder becomes a neutron star as protons and electrons are crushed together to form neutrons. Normal "main sequence" stars produce mostly helium. When the hydrogen is gone at the stellar ...
*Thursday, April 29, 2010 at 10:15pm by drwls*

**physics**

Two copper cylinders, immersed in a water tank at 46.3°C contain helium and nitrogen, respectively. The helium-filled cylinder has a volume twice as large as the nitrogen-filled cylinder. a) Calculate the average kinetic energy of a helium molecule at 46.3°C. b) Calculate the ...
*Sunday, January 1, 2012 at 9:37am by maria*

**physics**

Two copper cylinders, immersed in a water tank at 46.3°C contain helium and nitrogen, respectively. The helium-filled cylinder has a volume twice as large as the nitrogen-filled cylinder. a) Calculate the average kinetic energy of a helium molecule at 46.3°C. b) Calculate the ...
*Tuesday, January 3, 2012 at 12:51pm by maria*

**Physics**

Two copper cylinders, immersed in a water tank at 46.3°C contain helium and nitrogen, respectively. The helium-filled cylinder has a volume twice as large as the nitrogen-filled cylinder. a) Calculate the average kinetic energy of a helium molecule at 46.3°C. b) Calculate the ...
*Sunday, January 26, 2014 at 10:24pm by Lyra*

**Chemistry (balloon)**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.3 kg m-3. Under these conditions the total surface area of the balloon is 0.33 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 2:49am by T*

**Chemistry (balloon)**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.7 kg m-3. Under these conditions the total surface area of the balloon is 0.52 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 2:49am by .*

**CHEM**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.43 kg m-3. Under these conditions the total surface area of the balloon is 0.68 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 10:01am by Jaigaon*

**chemistry**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.53 kg m-3. Under these conditions the total surface area of the balloon is 0.2 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 9:33pm by mike*

**physics**

The yellow line emitted by a helium discharge tube in the laboratory has a wavelength of 587 nm The same yellow line in the helium spectrum of a star has a measured wavelength of 590 nm. Calculate the speed of the moving star.
*Friday, December 14, 2012 at 12:36pm by amy *

**Chemistry (balloon)**

A latex balloon, wall thickness 3.091 x 10-4 m, contains helium at a concentration of 0.94 kg m-3. Under these conditions the total surface area of the balloon is 0.53 m2. The diffusion coefficient of He in latex at room temperature is 4.9 x 10-9 m2s-1. Calculate the rate of ...
*Saturday, December 15, 2012 at 2:49am by anono*

**physics**

Tension = Bouyancy force - ballon weight - helium weight. = [V(air density - helium density) + ballon mass)]*g V = (4/3) pi R^3 g = 9.8 m/s^2 By multiplying by g, you get the answer in Newtons, which is probably what they want. For the air density, which you need, they should ...
*Monday, December 20, 2010 at 3:24pm by drwls*

**Physics**

A helium balloon lifts a basket and cargo of total weight 2250 N under standard conditions, at which the density of air is 1.29 kg/m3 and the density of helium is 0.178 kg/m3 . What is the minimum volume of the balloon? The acceleration of gravity is 9.81 m/s2 . Answer in ...
*Monday, December 5, 2011 at 11:31am by help*

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