Hi there! First we have to calculate the moles of LiOH. We will use LiOH's molar mass to find it
(12.092 g)(1mol/23.95g)=0.50 moles LiOH
Then we will use the formula of molarity which is moles of solute per L of solution
(0.50moles)/(0.125L)= 4.0391 M
Let us know if you have other questions!