How do you find a .2, and .4 molar solution of sucrose. *How many grams of sugar do you add to the water? How did you find that out?
The formula of sucrose is `C_12H_22O_11` .
Its molar mass=`12*12+22*1+11*16` =`342` g
The amount of sugar present in 1 litre 0.2 molar sucrose solution is `0.2*342=68.4` g
Similarly, the amount of sugar present in 1 litre 0.4 molar sucrose solution is `0.4*342=136.8` g
Hence, to prepare 1 litre 0.2 molar sucrose solution you need to take 68.4 g sugar in a volumetric flask first, then add distilled water, dissolving the solid gradually and finally make upto the 1 litre mark, stirring the solution throughout.
Similarly, to prepare 1 litre 0.4 molar sucrose solution you need to take 136.8 g sugar first and then fill the volume upto the mark stirring throughout.