Question

sodium phosphate is commonly found in processed meat and tuna. Calculate the concentration of sodium ions in a solution of .564 M

Answer 1

@Photon336

Answer 2

I'm doing a timed thing so I don't exactly have the time to go through the steps. But I can after I've finished.

Answer 3

@Photon336

Answer 4

let's start by writing the equation

Answer 5

Hang on. I put the wrong one. Sorry.

Answer 6

\[Na_{3}PO4(aq) --> 3Na ^{+} + PO4^{3-}\]

Answer 7

okay

Answer 8

C14H9Cl5 = 5.80 x 10^-8 M
5000L of water was tested
And it's wanting to know grams of C14H9Cl5 was found in the water sample.

Answer 9

Sorry about posting the wrong one.

Answer 10

no problem so you're given the molar concentration of this right? and the amount of water

Answer 11

Is that enough information to work with? I would type the full thing out but this thing is timed.

Answer 12

Yes

Answer 13

remember M = Mol/L

Answer 14

I got confused what I'm suppose to convert. Do I do all of the C14etc?

Answer 15

Well let's work with what you're being asked, you need to find the # of grams in your sample so what would you think you would need to do this?

Answer 16

the moles

Answer 17

exactly

Answer 18

they gave you the amount of volume in liters

Answer 19

what do you think we should do first when given the molarity, remember what molarity means.

Answer 20

use it to find the moles?

Answer 21

I mean we got morality and liters.

Answer 22

let me show you

Answer 23

\[Molarity = \frac{ moles }{ liter }\] follow?

Answer 24

Right

Answer 25

so watch when we multiply the molarity by the volume in liters we get the number of moles. can you see why this would be the case from what is shown below?

\[\frac{ moles }{ liter }*(\frac{ liters }{ 1 }) = moles \]

Answer 26

2.9 x 10^-4

Answer 27

Then using molar mass to convert it to grams it would be .10280 g. Sorry if I seem to be rushing. The thing I'm doing is timed and the time is running short on it.

Answer 28

\[5.80 x 10^-8 \frac{ mol }{ liters}*\frac{ (5000 liters) }{ 1 } = 2.9x10^{-4} moles\]

Answer 29

no problem the key here is about molarity you can always find the # of moles by multiplying by the volume of solvent by the molarity.

Answer 30

Is the .10280 grams right?

Answer 31

what's the molar mass that you have?

Answer 32

354.49

Answer 33

\[moles *\frac{ grams }{ mol } = grams\]

Answer 34

\[2.9x10^{-4} moles * (354.9 \frac{ grams }{ mol })\]

Answer 35

@staldk3 do you see a pattern like this? the unit that you don't want is in the denominator and cancels out and the unit you want is in the numerator.

Answer 36

Yeah. It always makes me happy when they cancel out. lol

Answer 37

So when I did it I got .1028021 grams.

Answer 38

yep did they ask for significant figures?

Answer 39

Yes so .103 grams?

Answer 40

yeah I think so because 2.9 has two significant figures so I think our answer should have two as well.

Answer 41

Wait should it be .10 then?

Answer 42

if I remember when you multiply numbers or divide your answer has the fewest significant figures.

Answer 43

So I think, that in 2.9 there are two significant figures and in 1.028021 there are like 7 so our answer should be .103 well .103 has 3 so it should have 2 I think it's .10

Answer 44

Alright. Thanks for helping so quickly!

Answer 45

yeah no problem

Answer 46

take care

Answer 47

You too