Question

What is the Na+ concentration in each of the following solutions:
3.65 M sodium sulfate:
2.18 M sodium carbonate:
0.985 M sodium bicarbonate:
What is the concentration of a lithium carbonate solution that is 0.595 M in Li+?

Answer 1

you need to know how many sodium \(ions\) make up every formula of those sodium salts. Sodium sulfate's formula is \(Na_2SO_4\), so every mole of sodium sulfate has \(TWO\) moles of sodium ions in it

Answer 2

Is there a certain formula I need? My class hasn't gone over this material yet.

Answer 3

you need to know how to turn names into formulas

Answer 4

I get that but what about the math portion?

Answer 5

the concentration of the sodium ion will depend on the number of sodium ions in that particular formula

Answer 6

if the solution is 3.5M sodium sulfate, the sodium concentration will be \(twice\) as large as the molecular concentration, because of \[Na_2SO_4(aq) \rightarrow 2Na^{+1}(aq) + SO_4^{-2}(aq)\]

Answer 7

So it would be 7M?

Answer 8

yes

Answer 9

And you do that for the rest of them essentially?

Answer 10

you look at the formula, you figure out how many ions of that type are in the formula, and you apply that to the concentration of the molecule to find the concentration of the ion

Answer 11

Alright. Will the Lithium carbonate be different?

Answer 12

Would you times the 0.595 by 2 since there are 2 lithium?

Answer 13

it will be doubled, because there are 2 lithium ions in lithium carbonate

Answer 14

L2CO3 what do you mean it doubles exactly? I'm confused about the doubling since I only see 2 lithiums. Can you explain please?

Answer 15

the lithium carbonate question is different, because it's asking you to go backwards

Answer 16

you're given the concentration of the \(lithium\) ions, but the concentration of \(Li_2CO_3\) will not be double, it will be half

Answer 17

So divide by the 2 instead?

Answer 18

yes

Answer 19

Thank you for the help