Question

What mass of barium chloride is present in a `100*mL` of barium chloride solution of `0.250*mol*L^-1` concentration?

Answer 1

Well, by definition, `"Concentration"="Moles of stuff"/"Volume of solution"`. I gets a mass of approx. `5*g`.

Explanation:

And thus, `"moles of stuff"="concentration"xx"volume of solution"`.

And in turn, `"moles of stuff"="Mass of stuff"/"Molar mass of stuff"`.

We have a `100*cm^3` volume of a `0.250*mol*L^-1` solution of `BaCl_2`. And `1*cm^3=1*mL=10^-3*L`.

And so .................`"moles of barium chloride"=100xx10^-3*cancelLxx0.250*mol*cancel(L^-1)`

`-=100xx10^-3xx0.250*mol-=0.0250*mol`.

The molar mass of barium chloride is `208.23*g*mol^-1`.

And thus `"mass"=0.0250*molxx208.23*g*mol^-1=??*g`.