Question

#1: If you want to make 0.5 L of a 0.01 M solution of bromine (Br2) in water, how much bromine would you need?

A. 0.8 grams

B. 0.8 moles

C. 1.6 grams

D. 1.6 moles

***my answer: C. 1.6 grams

is that right? @aaronq :)

Answer 1

#2: Which of the following statements is the correct definition of molarity?

A. number of moles of solvent/liter solution

B. number of grams of solvent/liter solution

C. number of moles of solute/liter solution

D. number of grams of solute/liter solution

***my answer: C

is that right? :/ not 100% sure...

Answer 2

1 is wrong :(

Answer 3

2 is right

Answer 4

darn :(

idk #1 then :( would it be D. 1.6 moles? not grams?

and yay for #2 tho! :D

Answer 5

\[M =\frac{ \frac{ 1.6g }{ 160g/mol } }{ 0.5L }\] = 0.02 M

Answer 6

#3: You add 0.5 moles of NaCl to water to make a 250 mL solution. What is the molarity of this solution?

A. 1.0 M

B. 2.0 M

C. 2.5 M

D. 4.0 M

***my answer: B. 2.0 M

is that right?

Answer 7

1.6/0.5 = 0.32 M so not that either

Answer 8

3 is good

Answer 9

okay, so i think it's grams tho right? so would that make it A. 0.8 grams?

Answer 10

yes, it's 0.8 g buuuut you should be able to work that out

Answer 11

#4: You have a 2.0 M solution of LiF. You had added 4.00 moles of LiF to a solvent to make this solution. What is the volume of this solution?

A. 2 L

B. 3 L

C. 6 L

D. 8 L

***my answer: A. 2L

is that right? :)

Answer 12

yeah haha i know! lol so idk how to do that then :(

can you please show me?

Answer 13

just use the molarity formula and try different values knowing the volume you're using

Answer 14

4 is good btw

Answer 15

#5: You have a solution made of 300 grams of ethanol (C2H5OH) and 500 grams of water. What is the mole fraction of ethanol in this solution?

A. 0.19 M

B. 0.81 M

C. 0.19

D. 0.81

***my answer: C. 0.19

is that right? :)

Answer 16

ohh okay i see :)

and yay for 4!! :)

what about 5? :/

Answer 17

5 is good (Y)!

Answer 18

omg! yay! =) thank you!!! :)

Answer 19

no problem !