Question

Help Please Last Question of the day......
A chemist studying the properties of photoraphic emulsions needed to prepare 500 mL
of 0.152 M AgNO3(aq). What mass of silver
nitratemust be placed into a 500mL volumetric flask, dissolved, and diluted to the mark
with water?
Answer in units of g

Answer 1

@Mertsj

Answer 2

First you need to plug all the numbers you have into the molarity equation which will give you .152=x/.500(your volume must be in liters) solve for x to get the number of moles and then you multiply your answer by the molar mass of silver to get the amount of grams

Answer 3

You're preparing 1/2 liter. If you wanted 1 Liter of solution you would use .152 moles of silver nitrate. Since you only want 1/2 liter you only need .152/2 moles or .76 moles of silver nitrate. So
1. calculate the molecular weight of silver nitrate
2. Multiply it by .76
3. Take that result write a "g" after it.
4. Put it in the appropriate sheet on you handout or whatever assignment I'm doing for you.

Answer 4

0.00023104g @Mertsj is that the answer?

Answer 5

i don't think that is the right answer

Answer 6

dont you just get .152 divide by 500 then multiply .76? @andrea723

Answer 7

I don't know because I don't know the molecular weight of silver nitrate.

Answer 8

What is it?

Answer 9

I rounded the molecular weight of silver nitrate to 170

Answer 10

What is 170 times .76?

Answer 11

1. calculate the molecular weight of silver nitrate

Answer 12

You said that is 170

Answer 13

129.2 @Mertsj

Answer 14

2. Multiply it by .76

Answer 15

i'm getting .076 to to multiply by because you do .500 L times the .152 for molarity

Answer 16

You said that is 129.2

Answer 17

3. Take that result write a "g" after it.

Answer 18

98.192g@Mertsj

Answer 19

What would that be?

Answer 20

the answer @Mertsj

Answer 21

So take that number 129.2 g and write it where you answer is supposed to be.

Answer 22

ok thank you i wrote down 129.2g is that right

Answer 23

yes

Answer 24

thats the wrong answer @Mertsj

Answer 25

Decimal point problem. 12.9 g

Answer 26

i find it easier to simply state the formula you're using and plug stuff in

so \[Molarity=\frac{ moles of solute }{ L _{solution} } = \frac{ (\frac{mass}{molar mass}) }{ L _{solution} }\]

plug in and solve for your unknown which would be the mass

Answer 27

Thank you both very much @Mertsj and @aaronq

Answer 28

yw