Thursday, June 2, 2011

Chemistry.. online test.. have 1 hr to complete.. please help!!!!!!!!!!!?

How many moles of oxygen (O2) must be placed in a container with a volume of 50.0 liters to produce a pressure of 4.50 atm at standard temperature? (Points: 1)

32 mol

7.5 mol

10.0 mol

28.0 mol





2. A sample of gas measures 3.50 liters at 273 K. At what temperature will its volume become 4.50 liters, assuming pressure remains constant? (Points: 1)

212 K

173 K

351 K

cannot be determined





3. A 5.0 liter tank of oxygen gas is at a pressure of 3.0 atm. What volume will be available if the oxygen is used at the normal atmospheric pressure of 1.0 atm? (Points: 1)

.6 liters

15.0 liters

1.67 liters

cannot be determined





4. What would happen to the pressure of a sample of gas if it were moved from sea level to 6.0 km above sea level? (Points: 1)

the pressure would stay the same

the pressure would be halved

the pressure would be doubled

the pressure would be tripled





5. R, the gas constant in the ideal gas equation, has a numerical value of 0.0821, what are the units? (Points: 1)

atm-liter/mol-K

atm-m3/mol-K

Pa-m3/mol-K

Pa-liter/mol-K





6. The most useful unit for describing the amount of gas is the: (Points: 1)

liter

cubic meter

mole

atmosphere





7. The temperature scale that has absolute zero as its zero point is the: (Points: 1)

Celsius scale

Kelvin scale

Rankin scale

Fahrenheit scale





8. The characteristics/variables of gases needed to describe a gas completely include all of the following except: (Points: 1)

pressure

temperature

density

volume





9. The ability of gas to spread rapidly through other gases is explained by: (Points: 1)

frequent inelastic collisions of the particles

the high density of gases

the high temperature of gases

constant random motion of particles





10. Collisions of gas particles in which no energy of motion is lost are called: (Points: 1)

perfectly elastic

mostly elastic

both elastic and inelastic

inelastic





11. Raising the temperature of a gas in a fixed volume container will most likely change the: (Points: 1)

number of particles in the container

density of the gas in the container

pressure exerted by the gas in the container

size of the gas particles in the container





12. Which of the following is not a property of gases? (Points: 1)

Gases can be compressed into smaller spaces

Gases diffuse throughout other gases

Gases exert pressure on objects

Gases are weightless near the surface of the Earth





13. Represented by “R” used in the ideal gas equation: (Points: 1)

ion

electronegativity

cathode ray

gas constant





14. What is the density (g / L) of CO2 at 25oC, 1.8 atm ? (R=.0821 L atm / K mol)? (Points: 1)

12.5

3.2

5.9

.088





15. How much faster is He gas than CO2? (Points: 1)

3.3

5.5

11.3

15.4





16. Real gases exist at: (Points: 1)

high temperature, high pressure

low temperature, low pressure

low temperature, high pressure

absolute zero





17. Which of the following is not part of the kinetic molecular theory? (Points: 1)

The higher the pressure of a gas, the higher the speed.

The lower the temperature of a gas the lower the speed.

Attractions between gas molecules are negligible.

The energy between gas molecules collisions are conserved.





18. How many moles of an ideal gas exist at 2.0 atm, 195 L, 25 oC ? (R = .0821 L atm / K mol )? (Points: 1)

2.0

4.0

16.0

32.0





19. Convert 250. ml of a gas at 25 oC, and 845 mm Hg to STP. (Points: 1)

255 mL

355 mL

455 mL

555 mL





20. As the pressure of a gas increases at constant temperature, the volume: (Points: 1)

stays the same

increases

varies up and down

decreasesChemistry.. online test.. have 1 hr to complete.. please help!!!!!!!!!!!?
Get working! You can not cheat on a test. Please give me your teacher's email so I can write him or her to let them know my answers if you want my answers to be given. You need to learn this material as it is relatively basic chemistry.Chemistry.. online test.. have 1 hr to complete.. please help!!!!!!!!!!!?
Sorry, I already have my Ph.D.; I am through with exams.



It's one thing to help a struggling student to gain a better appreciation for the subject, but I wouldn't go so far as to help him get a high mark in a subject he doesn't know that much about. It makes for very incompetent chemists later on. Go do something else, something you're actually good at.Chemistry.. online test.. have 1 hr to complete.. please help!!!!!!!!!!!?
Where I come from, a test, be it online, take=home, or in school, unless stated by the tester, is to be done by a student WITHOUT HELP. If you get such help, you are CHEATING!

That may be OK in your world, but not in mine.
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