How many liters of 1.2M solution can be prepared with 0.50 moles of C6H12O6

First you need to know the molecular weight of sugar (C6H12O6) which is 180.156g/mol

You have half a mole so you have 90.078g

If you wanted to make 1L of a 1.2M solution of glucose you would need 180.156*1.2=216.1872g

But you only have 90.078g

So you need to figure out how much this 90.078g will make if the solution must be 1.2M:

90.078g/216.1872g=xL/1L

solve for the X and you get 0.416666666 ...

so 416.7ml or 0.417L