Question

#1: You have four fixed-volume containers at STP. Container A has 0.5 mol of gas in 11.2 L. Container B has 2 mol of gas in 22.4 L. Container C has 1 mol of gas in 22.4 L. Container D has 2 mol of gas in 11.2 L. Which of the four containers have equal pressures?

A. A and B

B. A and C

C. B and C

D. C and D

**my answer: B. A and C

is that right? @UnkleRhaukus :)

Answer 1

#2: Why does opening the air valve of a tire at a constant temperature decrease the pressure?

A. The temperature decreases.

B. The volume decreases.

C. The atmospheric pressure decreases.

D. The number of molecules decreases.

**my answer: B. The volume decreases.

is that right?

Answer 2

#3: A student increases the temperature of a 200 cm^3 balloon from 60°C to 180°C. What will the new volume of the balloon be?

A. 100 cm^3

B. 236 cm^3

C. 272 cm^3

D. 600 cm^3

**my answer: B. 236 cm^3

is that right? :)

Answer 3

#4: In a reaction between vinegar and antacid tablets, the antacid is the limiting reagent. At constant pressure and temperature, three tablets produce 600 cm^3 of gas. What volume will four tablets produce?
A. 300 cm^3

B. 600 cm^3

C. 800 cm^3

D. 1,200 cm^3

**my answer: C. 800 cm^3

is that correct?

Answer 4

#5: You breathe in 12.0 L of pure oxygen at 298 K and 1,000 kPa to fill your lungs. How many moles of oxygen did you take in? (Use the ideal gas law: PV = nRT where R = 8.31 L-kPa/mol-K.)

A. 0.05 moles

B. 1.21 moles

C. 2.42 moles

D. 4.84 moles

**my answer; C. 2.42 moles

is that right?? @UnkleRhaukus :)

Answer 5

#1 is right

Answer 6

:) yay! what about 2-5? :D

Answer 7

try #2 again

Answer 8

ohh should it be A. The temperature decreases? and that is why it makes the pressure decrease? :/

Answer 9

nooope

Answer 10

i dont think #3 is right either

Answer 11

aww :( then idk :(

and oaky, so for 3 would it be C. 272 cm^3 ??? i wasn't too sure on that one.. :/

Answer 12

yeah that what i got for #3 because

200*453.15/333.15 =272

Answer 13

okay! :) and what about #2 then?

Answer 14

when you open the valvue on the tire, the high pressurised air rushes out

Answer 15

okay, so that means C. The atmospheric pressure decreases. ???

Answer 16

nope

Answer 17

the atmospheric pressure is not going to change because of one tire

Answer 18

aww :( so basically it's D. The number of molecules decreases. then?? (from process of elimination of my bad reasoning and answers lol) ??

Answer 19

yeah thats better

Answer 20

the molecules go out thought the valve

Answer 21

i think youve got #4 right

Answer 22

okay! Aweosme :) what about 5?

Answer 23

\[PV=nRT\\n=\frac {PV}{RT}\]

Answer 24

so i got #5 wrong? :(

Answer 25

\[n=\frac{1000[\text{kPa}]\times 12.0 [\text{L}]}{8.3[\text{L kPa /mol K]}298 [\text{K}]}\\=\frac{100\times12}{8.3\times298}[\text{mol}]\]

Answer 26

okay so 200/2473.4=0.08 ? :/

Answer 27

ops ** \[\frac{1000\times12}{8.3\times298}\]

Answer 28

=12000/2473
=

Answer 29

= 4.85

so the answer is D. 4.84 moles ???

Answer 30

thats it!

Answer 31

yay! thanks :)

Answer 32

yay! thanks :)