200 mg/L C12H22O11 mg/L as C;

Answer 1

Molar mass C12H22O11 = 342 g/mol

200 mg/L x 1g/1000 mg x 1 mol/342 g = 0.000585 mol/l

0.000585 mol/L x 12 mol C/mole C12H22O11 = 0.00702 mol C/L

0.00702 mol C/L x 12 g/mol = 0.0842 g C/L

Answer 2

200 mg/L C12H22O11

I think you mean this:

C12H22O11 molar mass = 342.3 g/mol (It's sucrose)

C12: 12 x 12.01 g/mol = 144.12 g/mol of C

144.12 g/342.3g = 0.42103418054 of the mass is carbon

200 g/L x 0.42103418054 = 84.2068361087g = 80 mg C/L, is sig figged to one place.