Show how to calculate the molarity of 45 g of hcl in 1.5 L of water


I showed you how to do this. It's two steps.

mols HCl = grams HCl/molar mass HCl
Take that number of mols you calculated and put it into the equation below.
Then M = mols HCl/L H2O.
What's your trouble? All you have to do is to substitute the numbers into the equations I gave you. I won't do it for you but I'll be glad to answer any questions that are confusing you.