## iheartfood 2 years ago #1: At STP, how many molecules of nitrogen gas are in 22.4 L? A. 6.022 × 10^22 B. 6.022 × 10^23 C. 6.022 × 10^24 D. 6.022 × 10^25 **my answer: B is that right?? @aaronq :)

1. iheartfood

#2: Molar mass is the molecular (formula) mass of any substance expressed in which of the following? A. moles B. grams C. kilograms D. liters **my answer: A is that right?

2. aaronq

molar mass is expressed in gram per mole

3. aaronq

1 is right though

4. iheartfood

#3: Which of the following temperatures and pressures are used as standards for gases? A. 0°C, 1 atm B. 25°C, 1 atm C. 10°C, 1 atm D. 5°C, 2 atm **my answer; A or is it B?? ;/ idk im a bit conflicted :/

5. iheartfood

okay so what is #2 then? ;/

6. aaronq

2 would be grams

7. aaronq

mass = unit of weight measurement

8. iheartfood

ohhh okay!! :) #4: Which of the following is NOT a measure of the amount of matter? A. mole B. molar mass C. molar volume D. STP **my answer; D is that right?

9. aaronq

STP, standard temperature and pressure ALWAYS 25 celsius and 1 atm (760 torr/mm Hg)

10. aaronq

4 is right

11. iheartfood

#5: Which of the following is equal to the number of particles in 18 grams of carbon-12? A. 1.5 : 1 mole ratio B. 1.5 : 1 molar mass c. 1.5 moles D. 1 : 1.5 molar volume *my answer: B is that right? :/

12. iheartfood

wait so #3 is B. 25°C, 1 atm ??

13. aaronq

yeah 3 is B. 5 is oddly worded, the only that makes sense is 1.5 moles because n=18g/12g/mol=1.5 moles

14. iheartfood

#6: Which of the following substances has a molar mass of 208 g? A. P2O5 B. BaCl2 C. AlCl3 D. MgCl2 **my answer; B is that right? :)

15. iheartfood

okay!! so #5 is what then?? :/

16. aaronq

5 would be 1.5 moles, C.

17. aaronq

6 is right (Y)

18. iheartfood

aweosme!! :) thx! #7: Who discovered the principle that equal volumes of gases at the same temperature and pressure contain the same number of particles? A. John Dalton B. Amedeo Avogadro C. Ernest Rutherford D. Jacques Charles *my answer: B is that right? :)

19. aaronq

yep! my main man avogadro

20. aaronq

21. iheartfood

#8: What is the volume of 1.5 moles of gas at STP? A. 9.02 L B. 20.0 L C. 33.6 L D. 22.4 L **my answer; C is that right??

22. iheartfood

LOL thats hilarious!!! :P

23. iheartfood

#9: You do an experiment in which you need 0.25 moles of tyrosine (C9H11NO3). How many grams must you weigh out? A. 45.3 g B. 90.5 g C. 181 g d. 272 g **my answer; A is that right? :)

24. aaronq

8 is good

25. aaronq

9 is also correct

26. aaronq

27. aaronq

this one you might not get

28. iheartfood

#10: For an experiment, you need to dissolve 0.10 moles of NaCl in 1 liter of water. How much NaCl must you weigh out? A. 8.2 g B. 5.8 g C. 3.2 g D. 0.14 g **my answer: B to is it A?? :/

29. iheartfood

lol yeah i get it, cuz h202 is hydrogen peroxide, which is poisonous and would kill u haha my friend told me this b4 lol

30. aaronq

hahaha wow, good stuff (Y)

31. iheartfood

#11: A doctor prescribes 1,500 mg of glucosamine (C6H13NO5) per day for a person with osteoarthritis. How many moles of glucosamine does the patient take each day? A. 8.38 B. 8.38 × 10^-3 C. 0.12 D. 1.79 × 10^-3 **my answer: B is that right? haha and yeah ikr?? :) so is #10 right?? is it B? or is it A? :/

32. aaronq

10 is right, B

33. iheartfood

#12: In a chemical reaction, you collect 500 mL of hydrogen gas at STP. How many moles of hydrogen gas did you collect? A. 22 B. 0.22 C. 0.02 D. 0.004 **my answer; C is that right?? and yayy :)

34. iheartfood

#13: How many atoms are in 1.0 moles of xenon gas at STP? A. 2.2 × 10^23 B. 3.0 × 10^22 C. 3.0 × 10^24 D. 6.0 × 10^23 **idk this one :( do u get it?

35. aaronq

11 is good!

36. iheartfood

yay :)

37. aaronq

12 is good

38. iheartfood

#14: A chemical reaction produces oxygen gas. You collect 6.02 × 10^23 oxygen gas molecules at STP. What volume of oxygen gas did you collect? A. 2.8 L B. 5.6 L C. 11.2 L D. 22.4 L **my answer; D is that irhgt?? :)

39. aaronq

for 13, you have to know that Xe(g) is not diatomic, so you know 1 mole = 6.022x10^23 atoms/molecules

40. aaronq

14 is good also!

41. iheartfood

annnndd last one!!! (which unfortunately i do not understand :(.... ) #15: A chemical reaction produces 5.6 L of nitrous oxide gas (N2O) at STP. What is the mass of the gas produced? A. 0.25 g B. 5.6 g C. 11 g D. 44 g ***idk :(

42. aaronq

43. iheartfood

so 13 would be D. 6.0 × 10^23 ??

44. iheartfood

lol that was a good one :P and that kitty is so cute with the glasses and stuff!! =)

45. aaronq

yes 13 is D, noble gases are ALWAYS unimolecular. uni=1

46. iheartfood

awesome! :)what about 15 tho?? and i found a good one hahaha :P i like this one :)

47. aaronq

so for 15, find how many moles you produced, 1 mole of gas at STP = 22.414 L so moles = 5.6/22.414 then use that to find the grams with the molar mass of N2O moles= mass/molarmass mass = moles*molarmass

48. aaronq

HAHA I've never seen that one, i like it

49. iheartfood

so is #15 A. 0.25 g?? and i found a kinda continued one of one u posted above :) and hahaa yeahh i like that one :)

50. iheartfood

lol

51. iheartfood

and this one :P

52. aaronq

nope! 11 g

53. aaronq

"ALL THESE CHEM JOKES ARE BORON ME" LOL

54. iheartfood

and i liked this one too :P

55. aaronq

56. aaronq

haha periodically

57. iheartfood

okay!! :) thanks!! :) and lol that ones good :) and heres another one.. but its with... the one and only!!! PAtrick... STar!!!!

58. aaronq

oh wait i added up the molar mass of N2O wrong i did NO2

59. aaronq

lol it's still 11 grams

60. iheartfood

okay!! haha thanks!! :D

61. aaronq

:) no prob haha i haven't watched spongebob in like i don't even know, forever.

62. iheartfood

haha yeah same, but i love patrick!! :) i mean he lives in a rock.. how do u even find a hollowed out rock?? :) spongebob is awesome!! :)the best cartoon ever!! :) lol thanks again!! :D

63. aaronq

it is so awesome, i liked the movie too! no problem at all!

64. iheartfood

yeah!! haha i watched it a while ago but all spongebob is good and funny :)

65. aaronq

agreed :) i'm gonna go, see ya !

66. iheartfood

byebye! :D