Question

Question #310dc

Answer 1

All this problem requires is that you know the mathematical definition of molarity (M):
`M`=number of moles (n) `-:` Volume (in Liters)

`M=n/V`

This question tells you the value of both M & n, all we must do is solve for V.

if `M=n/V` then `M*V=n` and finally `V=n/M`

We can check if this equation works by using only units and seeing if they cancel correctly.

`Liter=(mol)/((mol)/(Liter)` `->` `Liter=mol*(Liter)/(mol)`

Notice: the mol cancel out leaving us with Liters, so the equation must work.

Now let's plug in the given numbers:

`(3.00 mol)/(12M)=0.25L`

`0.25L*(1000mL)/(1L)=250mL` volume required (in mL) for a solution of 3.00 mole HCl to have a molarity of 12