How much 2% glucose solution can be made from 50.0 mL of 35% glucose solution?

978 ml
There are two approaches to this calculation. The first is a simplified method which assumes that the of the glucose solution is identical to that of water at room temperature around 1.000 g/ml.
The second method corrects for density of the glucose solution. This is more accurate especially if you preparing analytical in a laboratory.
The density of 35% m/m glucose solution is 1.126 g/ml
Ive estimated the density for 2% m/m glucose around 1.007 g/ml
You can get densities for glucose solution from the internet or use a chemistry handbook that contains properties of organic .
Note units are extremely important when doing calculations. Ive assumed your glucose solution is in weight percent ie m/m. This is how inorganic or organic solution densities are expressed in handbooks.
Lets start with the solution we have ie 50 ml glucose at 35% m/m
The mass of this solution can be calculated using the formula for density ie density = mass/volume
We know the density and volume. Therefore the mass of this solution is
50 ml x 1.126 g/ml = 56.3 g
Because our glucose solution is in weight percent we can easily determine the mass of glucose in solution. Ie
56.3x 35% = 19.7 g of glucose
Now the only way we can go from 35% to 2% is by dilution with distilled water. The dilute 2% glucose solution must contain the same amount of glucose.
The mass of this solution 19.7g/2%=985.3 g
Finally we use the density to determine the volume of this dilute solution = 985.3g/1.007 g/ml = 978 ml
If we used the simplified method we would obtain an answer of 875 g. Our error would have been 10.5%