1
$\begingroup$

I have to make a 250 mL solution of $\ce{Mg(NO3)2}$, the concentration of the solution has to be 0.3 mol/L. How can I find out the mass of how much $\ce{Mg(NO3)2}$ I need to use?

$\endgroup$
3
$\begingroup$

In 1 L there are 1000 mL and according to question there is 0.3 mol in 1000 mL. So, we can calculate how many moles should be there in 250 mL, i.e. (250/1000)*0.3 = 0.075 moles.

Now, let's find out the molecular mass of your compound i.e. 24 + 14*2 +16*6 = 148 u. So, by mole concept we know that there will be 148 g in 1 mole of your compound but you have 0.075 moles.

So the mass needed is (0.075/1)*148 = 11.1

Hope that makes sense !

$\endgroup$

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.