[chay722]

A mixture is prepared by adding 100 mL of .1 M AgNO3 to a 500 mL beaker containing 100 mL of .1 M Na2CrO4. I need to determine the number of moles in Ag+ in the Ag2CrO4. I know how to do it I just am unsure what the volume I should use should be. Should it be .2 L or .1L?  The reaction is the following 2AgNO3 + Na2CrO4 --> Ag2CrO4 + NaNO3

[ARGOS++]

Dear Chay722;

Sorry!,   ─   Do you know what you are asking?

What do you know about Ag₂CrO₄?     Why is it built?

Are you asking how much Ag⁺ is in Solution, or how much is in the Compound?

Good Luck!
                    ARGOS⁺⁺

[chay722]

I'm asking how many moles  Ag+ are in the Ag2CrO4. I know that the molarity of the Ag+ is .1M, now all I need to determine the moles is to multiply that .1M by the volume.

[ARGOS++]

Dear Chay722;

If I remember correctly you were asking a little before:

Why they talked about the liquid Phase?

Have you ever thought about the Solubility of Ag₂CrO₄?
(“Wiki” knows it!)

Thereafter  you may ask again.

Good Luck!
                    ARGOS⁺⁺

[chay722]

The Ag2CrO4 is a precipitate and therefore insoluble but what does that tell me about the volume?

[ARGOS++]

Dear Chay722;

How big is the Volume of your Precipitate?

Good Luck!
                    ARGOS⁺⁺

[chay722]

I don't know, that's what I'm asking haha.

[ARGOS++]

Dear Chay722;

How big is the Volume of your Precipitate?

If you really like you can calculate it with the Density of Ag₂CrO₄.
(“Wiki” tells it is 5.625 g/ml for the Solid!)

But I don’t believe that gives you the answer you have to find.


Good Luck!
                    ARGOS⁺⁺

[chay722]

I don't have the mass so I couldn't calculate the volume anyway. I have 100 mL and 100 mL in the reactants so would my two products simply be 100 mL and 100 mL ?

[enahs]

Ok, let me try this.

I need to determine the number of moles in Ag+ in the Ag2CrO4

Now, are you saying you need to determine the number of moles in Ag in Ag2CrO4?

If so, is it not reasonable to look at what is added to the system? Ag is only coming from one source, correct? Can you get more out then you put in?

In short, how many moles of Ag was put into the system?

This is a very easy problem.

It is a very different problem if you where told how many moles of AgNO3 was put in, and asked for how many moles of Ag2CrO4 were produced. As in that case 2 -> 1 as in your balanced equation.

Make sure you have to correct question.

[chay722]

It only tells me how many moles of AgNO3 are put in, but I need to find out how many moles of just Ag+ are produced in the Ag2CrO4.

[ARGOS++]

Dear Chay722;

If we assume the Questions goes more the way as Enahs believes:
How many Moles Ag⁺ you have added?
(How much Moles are in 100 mL of 0.1 molar Solution?)

And as Enahs has already told you, that more then enough Na₂CrO₄ is present:
How much moles  Ag₂CrO₄ are you able to build?

Good Luck!
                    ARGOS⁺⁺