Answer:
There are needed 237.15 g of sucrose.
Explanation:
The 31.0 % (w/v) of the sucrose solution means that in 100 ml of solution, you have 31 g of solute, in this case sucrose.
So you want to make a solution with 765 mL.
Let's think the rule of three:
100 mL solution__contain __31 g sucrose
765 mL solution _________ (765 . 31 ) /100 = 237.15 g