Monday

July 28, 2014

July 28, 2014

Number of results: 57,727

**chemistry**

How many moles of helium gas would it take to fill a balloon with a volume of 1000.0 cm^3 when the temp is 32 degrees C and the atmospheric pressure is 752 mm Hg
*April 29, 2008 by jerson*

**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 ...
*April 6, 2011 by Paxton*

**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 ...
*April 15, 2007 by Mary*

**Chemistry**

A helium balloon contains 0.54g of helium. Given the molecular weight of helium is 4.0 g/mol, how many moles of helium does it contain?
*February 22, 2013 by Mira*

**Chemistry**

A helium ballon contains 0.32g of helium. Given the molecular weight of helium is 4. How many moles of helium does it contain.
*March 31, 2014 by Anonymous*

**chemistry**

You have 120 grams of U-235. How many half lives would it take to make enough helium to fill a 5.60 L balloon at STP?
*July 3, 2013 by Mary*

**chemistry**

A helium balloon contains 0.26 g of helium. How many moles of helium does it contain?
*November 17, 2008 by pip*

**chem**

A typical party balloon when inflated has a volume of 7.3 L. How many moles of helium are in the balloon if the pressure of helium is 1.2 atm and the temperature is 20.7 °C? Take the value of R to be 0.08206 L-atm/mol-K.
*July 26, 2012 by hhh*

**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
*October 21, 2007 by lt*

**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
*October 23, 2007 by LT*

**Math **

Two taps, having different rates of flow are used to fill a large water tank. If tap A is used on its own it will take 5 hours longer to fill the tank that it would take tap B to fill it on its own. Together, the taps would fill the tap in 6 hours. Assuming that the taps are ...
*September 10, 2010 by Jamie*

**Math**

Four hoses are filling a pool. The first hose alone would fill the pool in 4 hours while the second hose takes 6 hours. The third hose and the fourth hose each take 8 hours to fill the pool. How long would it take to fill the pool if all 4hoses are turned on?
*November 20, 2013 by Kristen*

**chemistry**

A helium-filled balloon of the type used in long-distance flying contains 420,000 ft3 (1.2 times 107 L) of helium. Suppose you fill the balloon with helium on the ground, where the pressure is 737 mm Hg and the temperature is 16.0 °C. When the balloon ascends to a height of 2 ...
*March 30, 2007 by Helpme*

**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 ...
*December 1, 2006 by maysam*

**physics**

Helium balloons are used regularly in scientific research. A typical balloon would reach an altitude of 45.0 km with an air density of 4.3×10−3 kg/m3. At this altitude the helium in the balloon would expand to 540000.0 m3. Take g=10 m/s2. Find the buoyant force on the ...
*December 14, 2013 by Anonymous*

**math**

One pipe can fill a pool in 20 minutes, a second can fill the pool in 30 minutes, and a third can fill it in 10 minutes. How long would it take the three together to fill the pool?
*July 16, 2013 by vinci*

**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 helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721mmHg? Express your answer ...
*October 10, 2010 by Ellen*

**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 Helium is present in a helium-oxygen mixture having a density of 0.538 g/L at 25 degrees C and 721 mmHg? Express your answer ...
*October 10, 2010 by Ellen*

**chem1 WORD PROBLEM!!**

6. how many grams are in 4 moles of Be (OH)3? 7.How many atoms are in 4 moles of C6H12O6? 8.how many moles are in 12.04x10 23 to the power molecules of hamburgers? 9. how many molecules are in grams of Helium gas (He2)? hint:convert then moles then moecules
*December 6, 2012 by tyneisha*

**college algebra**

A paint-mixing machine has 2 inlet pipes. One takes 1 hour less than the other to fill the tank. Together they fill the tank in 3 hours. How long would it take each of them alone to fill the tank? Thank you!!!
*October 15, 2008 by jenny*

**Chemistry**

Please tell me which Gas Law equation to use to figure out this problem... A helium balloon at 25°C, 1 atm, has a volume of 2.88 L. Additional helium is pumped into the balloon. It now contains 1.20 g of He and its new volume is 7.20 L. How many moles of helium gas did the ...
*March 23, 2013 by Pam*

**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 ...
*November 6, 2009 by John S.*

**akgebra**

One pipe can fill a tank in 20 minutes, while another takes 30 minutes to fill the same tank. How long would it take the two pipes together to fill the tank?
*April 24, 2013 by jj*

**chemistry**

A gaseous mixture containing 6 moles of oxygen, 8 moles of helium and 6 moles of carbon dioxide in a container under a pressure of 40 atm. Calculate the partial pressure of th3 individual gases.?
*May 30, 2013 by sagar*

**chemistry**

the helium in a 1.5L flask at 25degrees celcius exerts a pressure of 56.65kPa. How many moles of helium are in the flask?
*January 30, 2013 by amber*

**Chemistry**

A 6.00 ft cylinder has a radius of 26 in. It contains 189 lb of helium at 25 celsius. Express the volume of the cylinder (V=ðr²h) in liters, the amount of helium in moles and the temperature in Kelvin.
*September 27, 2012 by Wendy*

**Chemistry**

How many moles of a gas at 100 degrees celciuos does it take to fill a 1.00 flask to a pressure of 1.50 atm?
*November 19, 2010 by Natalia*

**physics**

What would happen the the wavelength of an organ pipe if you fill it with helium instead of air? What would happen to the fundamental frequency? Explain Please show all work, Thank you
*May 2, 2011 by silly*

**Physics plzzzzzzzzz help**

Ideal Gas Law: PV = N k T ---> N = PV/(k T) N = 1.387*10^(29) mass of one helium atom is approximately 4*u = 6.642*10^27 kg 4u*N = 921 kg 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 ...
*December 1, 2006 by Count Iblis*

**math**

Jane needs to fill her pool with water. Ace said it will take them 40 minutes to fill the pool. Ben said it will take them 60 minutes to fill the pool. How long it will take for both Ace and Ben to fill the pool at the same time?
*April 6, 2012 by james*

**ap chem**

A mole of helium gas contains 6.02x10^23 helium atoms. How many helium atoms are there in a micromole of helium? How many moles of helium does 1.25x10^20 atoms of helium represent? ~I have no idea how to start or what the value of a micromole is? Constructive help would be ...
*December 13, 2006 by sara*

**physics**

A portable steel tank with a volume 35 liters (0.035m³) holds helium gas used for filling party balloons. The pressure in the tank is 120atm when at room temperature of 22 °C. How many moles of helium gas are in the tank? Each balloon has a volume of 2.5liters when filled with...
*January 4, 2012 by sand*

**Math**

Jim can fill a pool in 30 min, sue can do it in 45 min, Tony can do it in 90min, how long would it take all three to fill the pool together? How would i figure this out?
*June 28, 2012 by Anonymous*

**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.
*September 2, 2010 by paulie*

**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
*February 21, 2011 by Anonymous*

**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 ?
*September 7, 2012 by whitney*

**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 ...
*September 8, 2012 by Cassidy *

**MATH**

An inlet pipe can fill an empty pool in 3 hours. Another pipe can fill the same pool in 4 hours. How long will it take to fill the pool if both pipes are on? how would this equation be set up?
*September 25, 2008 by jennifer*

**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?
*May 1, 2010 by Amy *

**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 ...
*October 28, 2007 by K*

**Chemistry **

A 1.50mol sample of helium at a certain temperature and pressure has a volume of 31.4L. A second sample of helium at the same temp and pressure has a volume of 42.2L. How many moles of Helium are in the second sample?
*March 3, 2011 by naseeb*

**Physics**

Useful Constants: 1 Torr = 133.32 Pa; R = 8.3145 J/mol·K You have a thin metal sphere of unknown volume that contains helium gas at low pressure. You put the entire metal sphere into a bath of liquid nitrogen, and a pressure gauge on the sphere indicates a pressure of 288 torr...
*November 16, 2009 by Ellie*

**construction**

A swimming pool is 120' long,45' wide and 10' deep.How long would it take to fill with water if your maximum fill rate was 15 gallons per minute?
*July 26, 2011 by Mark*

**Chem hw!**

1. What pressure would be needed to compress 25.1 mL of hydrogen at 1.01 atm to 25% of its original volume? 2. If the pressure on a 1.04-L sample of gas is doubled at constant temperature, what will be the new volume of the gas? 3. A 1.04-L sample of gas at 759 mm Hg pressure ...
*March 11, 2010 by Teisha*

**Chem hw!**

1. What pressure would be needed to compress 25.1 mL of hydrogen at 1.01 atm to 25% of its original volume? 2. If the pressure on a 1.04-L sample of gas is doubled at constant temperature, what will be the new volume of the gas? 3. A 1.04-L sample of gas at 759 mm Hg pressure ...
*March 11, 2010 by Teisha*

**algebra**

Two pumps can fill a water tank in 256 minutes when working together. Alone, the second pump takes times as long as the first to fill the tank. How many minutes would it take the first pump to fill the tank?
*October 28, 2012 by tiffany*

**algebra**

At the station, you fill the tank. You use an overhead fill that puts out 162 gallons per minute. How long will it take to fill the tank?
*July 2, 2014 by floyd*

**chemistry**

1.50 mol sample of helium at a certain pressure and temperature has a volume of 31.4 L. a second sample of helium at the same temperature and pressure has a volume of 42.4 L. Therefore the second sample contains how many moles of helium?
*April 30, 2014 by Anonymous*

**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 ?
*October 7, 2012 by Ayesha*

**sciencee**

1. What pressure would be needed to compress 25.1 mL of hydrogen at 1.01 atm to 25% of its original volume? 2. If the pressure on a 1.04-L sample of gas is doubled at constant temperature, what will be the new volume of the gas? 3. A 1.04-L sample of gas at 759 mm Hg pressure ...
*March 9, 2010 by Teisha*

**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 ?
*September 26, 2008 by tomi*

**Physics**

a tank of helium gas used to inflate toy baloons is a pressure of 15.5 x 10 Pa and a temp of 293 k. The tank's volume is 0.020 m. How are a baloon would it fill at 1.00 atmosphere and 323 k
*April 25, 2010 by Rita*

**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 ?
*May 4, 2013 by molly*

**CHEm**

Amount of Helium in a Blimp The Goodyear blimp Spirit of Akron is 62.6 m long and contains 7023 m^3 of helium. When the temperature of the helium is 280K , its absolute pressure is 110kPa . Find the mass of the helium in the blimp. m=_____kg ty
*April 16, 2014 by Brady*

**chemistry**

Initially, there are 33 moles of A and 0 moles of B. How many moles of A and B will be present after the system reaches equilibrium? a) 33 moles A; 0 moles B b) 0 moles A; 33 moles B c) 3 moles A; 30 moles B d) equal amounts of A and B The answer is given as "C" but I dont ...
*April 27, 2011 by Adam*

**Algebra**

Two hoses are connected to a swimming pool. Working together, they can fill the pool in 4 hr. The larger hose, working alone, can fill the pool in 6 hr less time than the smaller one. How long would it take the smaller one, woking alone, to fill the pool? Please explain
*November 4, 2011 by Megan*

**Math**

Two hoses are connected to a swimming pool. Working together, they can fill the pool in 4 hr. The larger hose, working alone, can fill the pool in 6 hr less time than the smaller one. How long would it take the smaller one, woking alone, to fill the pool? Please use the work ...
*November 5, 2011 by Skylar*

**science**

what volume of helium would be in a balloon the size of a soft drink bottle? Depends on the size of the soft drink bottle. . . . The worksheet didn't specify the size. It wants us to apply strategies. Thank you.... i'm assuming about the same volume as in the bottle Volume of ...
*February 27, 2007 by deb*

**science**

how grams it would take to fill the buret to 35mL? is this would take more or less than for butane? what do you think causes this value to be different from the value for butane?
*July 9, 2011 by baby1*

**chemistry**

The first step in the Ostwald process for making nitric acid is the formation of NO as follows; 4HN3 + 5O2 makes 4NO + 6 H2O. According to the equation, 5 moles of NH3 will react stoichiometrically with blank moles of O2 to form blank moles of NO. I can't figure out how to ...
*October 19, 2010 by lavonne*

**Algebra**

There is a water tank with a drain of an unknown size that is always open. There is a series of input pipes above it which are all the same size. When 4 pipes are on, it takes 6 hours to fill. When 3 pipes are on, it takes 10 hours to fill. How many pipes would it take to fill...
*June 26, 2012 by Jimmy*

**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 ...
*January 31, 2007 by smart monkey girl96*

**Physics**

A spherical helium filled balloon is attached to a string that is fixed to the ground. the balloon has a volume of .30/4m^3 and helium has a density of .20 kg/m^3. What is the weight of the balloon and helium if the tension on the string is .8N? What is the Gravitational force...
*October 11, 2013 by George*

**Physics**

A spherical helium filled balloon is attached to a string that is fixed to the ground. the balloon has a volume of .30/4m^3 and helium has a density of .20 kg/m^3. What is the weight of the balloon and helium if the tension on the string is .8N? What is the Gravitational force...
*October 11, 2013 by George*

**math**

you fill up 40 gallon pool putting in 2 gallons water every minute, if someone scoops out 1 gallon every 8 minutes, how long would it take to fill the pool?
*January 24, 2013 by Lisa*

**Math**

Two taps named tap A and B are used to fill a tank. Tap A on its own takes 5 hours longer than tap B to fill the tank. The two taps working together fill the tank in 6 hours. How long does it take tap A to fill the tank on its own? How long does it take tap B to fill the tank ...
*September 10, 2010 by Jamie*

**chemisrty**

Q2) If 0.327 moles of H2S effuses in 462 seconds, how many seconds would it take for the same number of moles of CH3Cl to effuse?
*January 16, 2012 by lyan*

**chem**

A balloon holds 29.3 kg of helium. What is the volume of the balloon if the final pressure is 1.2 atm and the temperature is 22°C? using the equation pv=nrt would i put 29.3 kg in place of n? but n has to be in moles so how do you convert that? thanks
*February 14, 2011 by hannah*

**Math**

Two faucets can fill a tank in 1 hour and 20 minutes. The first faucet takes more than two hours longer to fill the same tank when functioning without the second tap. How long does it take to fill each one separately? Explain your solution
*October 22, 2011 by Louis*

**Chemistry**

when doing a lab experiment on limiting reagents for CoCl2 there is a chart to fill out that says to find the concentration of test tubes 1-6, find the volume delivered and find the moles of CoCl2. How would I find the moles of CoCl2 for each test tube?
*October 5, 2011 by Hannah*

**Chemistry**

Consider the gas-phase equilibrium A ⇌ B. In a series of experiments, different initial amounts of A and B are mixed together, and the mixture in each case is allowed to come to equilibrium. Which one of these experiments would yield values for the amounts of A and B ...
*March 8, 2010 by Val*

**Chemistry**

Consider the following balanced equation: 2N2H4(g)+N2O4(g)→3N2(g)+4H2O(g) Complete the following table showing the appropriate number of moles of reactants and products. If the number of moles of a reactant is provided, fill in the required amount of the other reactant, ...
*March 5, 2014 by Carter*

**math**

An inlet pipe can fill an empty pool in 3 hours. Another pipe can fill the same pool in 4 hours. How long will it take to fill the pool if both pipes are on? time=1pool/(1pool/3 + 1pool/4) Notice the rates add..1pool/4hrs + 1pool/3hrs. time=12/7 hrs so would this be 7 hrs or ...
*September 27, 2008 by jennifer*

**Math**

3 pipes are used to fill apool with water .Individually they can fill that pool in 9hr ,6hr ,3hr .how many minutes will it take to fill the pool if all 3 pipes are used simultaneously?
*March 5, 2011 by rob*

**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 ...
*November 29, 2010 by Lindsay*

**math**

Filling a tank. Two pipes are connected to the same tank. Working together they can fill the tank in 4 hrs. The larger pipe working alone can fill the tank 6 hrs less than the smaller one, HOw long would the smaller one take, working alone, to fill the tank?
*June 21, 2011 by AJA*

**math**

bob can fill bucket in 25 seconds in the sink, sue can fill same bucket in 17 seconds with hose, how much longer will it take bob to fill 15 buckets
*January 15, 2013 by Jen*

**College Physics**

If one micrometeorite (a sphere with a diameter of 1.8 10-6 m) struck each square meter of the Moon each second, estimate the number of years it would take to cover the Moon with micrometeorites to a depth of one meter? Find how long it would take to fill the box.
*January 18, 2011 by Myriam*

**math**

If pump A and pump B work together, they can fill a pool in 4 hours. Pump A, working alone, takes 6 hours to fill the pool. How long would it take pump B, working alone, to fill the pool?
*January 31, 2013 by Randy*

**12th grade physics**

Helium is monatomic with a relative atomic mass of 4. calculate (i) the density of helium gas at a temperature of 0 degrees Celsius and a pressure of 101kPa and (ii) the rms speed of the helium atoms under these conditions
*September 20, 2010 by Enya*

**Chemistry**

A tank contains helium for filling balloons. It holds 6.75 L of Ne at 24.8 atm and 27.5 °C. What would be the volume of this helium at 2.13 atm and 10.6 °C?
*May 6, 2014 by Aleena *

**Physics**

The boiling point of helium at 1 atm is 4.2 K. What is the volume occupied by helium gas due to evaporation of 70 g of liquid helium at 1 atm pressure and a temperature of 6.2 K?
*February 24, 2012 by Gabe*

**Chemistry**

Given the balanced equation representing a reaction : 2Fe+ 3Cu^2+ --> 2Fe^3+ +3Cu When the iron atoms lose six moles of electrons, how many moles of electrons are gained by the copper ions? (1) 12 moles (2) 2 moles (3) 3 moles (4) 6 moles how would i even start solving a ...
*February 16, 2014 by Anonymous*

**Chemistry**

Consider the gas-phase equilibrium A ⇌ B. In a series of experiments, different initial amounts of A and B are mixed together, and the mixture in each case is allowed to come to equilibrium. Which one of these experiments would yield values for the amounts of A and B ...
*March 8, 2010 by Val*

**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.
*December 24, 2013 by Hil*

**Physics**

A sealed container of volume 0.10 m3 holds a sample of 3.0 x 10^24 atoms of helium gas in equilibrium. The distribution of speeds of helium atoms shows a peak at 1100 ms-1. Caluculate the temperature and pressure of the helium gas. (helium atom 4.0 amu) How do I calculate the ...
*May 19, 2008 by Oli*

**math**

Three water pipes are used to fill a swimming pool. The 1st pipe alone takes 8 hours to fill the pool, the 2nd pipe alone takes 12 hours to fill the pool, and the 3rd pipe takes 24 hours to fill the pool. If all 3 pipes are opened at the same time, how long will it take all 3 ...
*May 26, 2011 by bob*

**chemistry**

CoCl3(aq) + K2S(aq) yield Co2S3(s) + KCl(aq) How many moles of KCl would be produced when 0.470 moles of Co2S3 are produced in the above unbalanced reaction? How many moles of K2S would be required to react with 0.940 moles of CoCl3? How many moles of K2S would be required to ...
*November 12, 2010 by sarah*

**physics**

A Goodyear blimp typically contains 5400m^3 of helium (He) at an absolute pressure of 1.1*10^5Pa. The temperature of the helium is 280K. What is the mass (in kg)of the helium in the blimp? PLEASE GIVE ME SOME IDEAS TO DO IT!!!THANKS A LOT!!!
*February 21, 2008 by Amanda*

**math**

Hose A can fill a pool in 4 hours. Hose B can fill the pool in 2 hours.If both hoses are turned on at the same time, how long will it take the pool to fill?
*September 27, 2010 by neena*

**Math **

If it takes 4 minutes to fill a bucket with one tap and 6 minutes to fill the bucket with another tap. Using both taps how many seconds will it take to fill the bucket?
*February 4, 2013 by Clara *

**science**

how would 10 grams of helium be different that 10 grams of helium in a sealed container.
*December 9, 2013 by jaylon*

**chemistry**

A slab of plate glass containing dissolved helium is placed in a vacuum furnace at a temperature of 400 C to remove the helium from the glass. The concentration of helium is constant throughout the glass before vacuum heat treatment. After 10 minutes in vacuum at 400 C, at ...
*December 21, 2013 by Dick*

**Algebra**

1) Mio can build a large shed in 15 days less than Yuuko can. If they build it together, it would take them 18 days. How long would it take each of them working alone? M: Y: 2) A sink can be filled by a pipe in 6 minutes but it takes 12 minutes to drain a full sink. If both ...
*November 6, 2013 by Vice*

**Physics please help !**

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? You asked this twice. See my response to your later post.
*December 1, 2006 by maysam*

**Chemistry**

Bill and Bob have been testing a new aluminised PET (Polyethylene Terephthalate) film and they now use the material to make helium filled balloons. Bill’s balloon is less inflated than Bob’s, and the latter jokes about it. However, Bill insists he has to be careful because if ...
*February 8, 2012 by MM*

**Chemistry**

Bill and Bob have been testing a new aluminised PET (Polyethylene Terephthalate) film and they now use the material to make helium filled balloons. Bill’s balloon is less inflated than Bob’s, and the latter jokes about it. However, Bill insists he has to be careful because if ...
*February 8, 2012 by MM*

**Algebra**

2 pumps can fill a water tank in 45 minutes when working together. Alone, the second pump takes 3 times longer than the first to fill the tank. How long does it take the first pump alone to fill the tank? Show all work
*October 9, 2011 by Anne*

**college algebra**

water from a tank is being used for irrigation while the tank is being filled. The two pipes can fill the tank in 6h and 8h, respectively. the outlet pipe can empty the tank in 24h. How long would it take to fill the tank with all three pipes open? round the answer to the ...
*December 12, 2012 by Zachery*

**AP Chem**

Can someone please check these problems? 34. You fill a balloon with helium gas to a volume of 2.68 L at 23 degrees C and 789 mmHg. Now you release the balloon. What would be the volume of helium if its pressure changes to 632 mmHg but the temperature is unchanged? 3.35 L 38. ...
*November 12, 2008 by Anna*

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