There are 2 moles in 8 grams
B) 2
You would first balance GO4 by adding a coefficient of 3 in front of DnGO4 in the reactants. Then you’d balance the 3DnGO4 by adding a coefficient of 3 in front of Dn in the products. Finally you’d balance Eg by adding a coefficient of 2 in front of Eg to balance with the Eg2(GO4)3 in the products.
You start by using proportions to find the number of liters of solution:
180 g of glucose / 1 liter of solution = 18 g of glucose / x liter of solution
=> x = 18 g of glucose * 1 liter of solution / 180 g of glucose = 0.1 liter of solution.
If you assume that the 18 grams of glucose does not apport volume to the solution but that the volume of the solution is the same volumen of water added (which is the best assumption you can do given that you do not know the how much the 18 g of glucose affect the volume of the solution) then you should add 0.1 liter of water.
Answer: 0.1 liter of water.