Question

How many moles are in sodium chloride in 150 mL of a 2 mM NaCl solution?

Answer 1

`"Concentration"="Moles of solute"/"Volume of solution"`. And here there are:
`150xx10^-3cancelLxx2xx10^-3*mol*cancel(L^-1)=3.00xx10^-4*mol` of solute.

Explanation:

`"Concentration"="Moles of solute"/"Volume of solution"`

And thus `"moles of solute"="volume"xx"concentration"`

And here, for this product we have:

`150xx10^-3cancelLxx2xx10^-3*mol*cancel(L^-1)=3.00xx10^-4*mol`.

(I have changed the volume from `mL` to `L`, and from `mmol` to `mol` simply by using the appropriate multiplier.