Question

Given a `6.174*g` mass of sodium sulfate that is dissolved in a `1*L` volume, what is the concentration in terms of `"parts per million"` with respect to sodium ion?

Answer 1

With respect to sodium ion, we have a `"2000 ppm"` concentration.

Explanation:

`"1 ppm"` specifies `1*mg` of solute per litre of solution......

We has `((6.174*g)/(142.04*g*mol^-1))/(1*L)=0.0435*mol*L^-1` with respect to sodium sulfate....

And thus `2xx0.04346*mol*L^-1=8.693xx10^-2*mol*L^-1`, with respect to sodium ion. Why did I double the concentration of sodium sulfate?

And thus, with respect to sodium ion, we have a concentration by mass of ........

`8.693xx10^-2*mol*L^-1xx22.99*g*mol^-1=2.000*g*L^-1`.

But `"1 ppm"` `=` `1xx10^-3*g*L^-1`, i.e. `1*mg*L^-1`, and thus we have.....

`2.000*g*L^-1xx10^3*mg*g^-1=2000*mg*L^-1-=2000` `"ppm"`.