Question

How many grams of glucose (MW = 180 g) should we dissolve in one liter of water to get 1 molar solution?

Answer 1

There is no way to get 1 M glucose that way since one doesn't know how much volume is occupied by the dissolving glucose. You do it by dissolving 1 mol glucose (180 g) in some water, then MAKING TO A FINAL VOLUME of 1 L. That way the final volume is exactly 1L BUT we don't know exactly how much water we added. (OK, there are ways to know but not without more information than you've given.)