Can you check if my steps are correct to this problem??

Question

You have prepared a solution by dissolving 73.15mg of sucrose (table sugar, C12H22O11) in 1.55kg of water. What is this solution's sucrose concentration in parts per million, ppm?

ppm= [(73.15/1000)/1550]x 10⁶

=47.194= 47.2 ppm and put this to 3 sig figs. Do we need to include the molar mass of sucrose other wise the answer if we were to add the molar mass of sucrose it would be 0.137 ppm. I don't know if this right though

Answer 1

We do not need to include the molar mass of sucrose. You simply find the grams of sucrose and divide it by the grams of water and then convert to g sucrose per million grams of water. You set up the calculations correctly, but made a math error. I believe you are off by a factor of 10.

grams sucrose = 73.15 mg x 1 g / 1000 mg = 0.07315 g sucorse

grams water = 1.55 kg x 1000 g / kg = 1550 g water

ppm = 0.07315 / 1550 (x10⁶) = 472 ppm