Chemistry
posted by Steve .
A student placed 12.0g of glucose (C6H1206) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100.ml mark on the neck of the flask was reached. The flask was then shaken until the solution was uniform. A 50.0ml sample of this glucose solution was diluted to 0.500 L. How many grams of glucose are in 100 ml of the final solution?

12.0 g/100 mL 0riginal.
Take a 50.0 mL aliquot so now you have 6.0 g in the 50.0 mL. That is diluted to 500 mL so now you have 6.0 g in 500 mL. If you take 100 mL of that solution you will have 1/5 of 6.0 = ?? 
12545

m=12grams
Molar Mass= 180.18
V=.1L
n= m/MM= 0.067 moles.
Molarity= n/V= .067/.1= .67
M1V1=M2V2 => 0.67(.05)=M2(.5)
Solve for M2 and you get .067
M= m/VMM : Molarty= mass/ Volume x Molar Mass
so m= MVMM : mass= Molarity x Volume x Molar Mass
m= .067(.1)(180.18)= 1.21
Just the steps to Dr.Bob's work :)