Mass calculation

[ravenhawk_49417]

I am creating an unknown riboflavin solution. I have a mulit-vitamin tablet weighing 0.849g. The bottle says there is 10g of riboflavin in each tablet. The tablet was crushed up and I took 0.201g of the powder and mixed it in 250mL of distilled water. I need to calculate the mass of riboflavin in the entire unknown solution and I am not sure how to set it up.

 

At first I thought you take the 0.849g tablet/10g riboflaven = X/.201g vitamin sample. then X would equal 0.422g riboflavin but where does the 250ml of water in the solution come into play?

[a_j]

I think u twisted the formula. In ur case u get an unit that means 1/g for a mass and I think the units are wrong.

 

the concentration of a solution is calculated by (c (mg/L) = mass (mg)/V (L))

 

Hope this helps...

Edited September 8, 2011 by a_j

[ewmon]

I have a mulit-vitamin tablet weighing 0.849g. The bottle says there is 10g of riboflavin in each tablet.

First, a 0.849 g tablet cannot contain 10 g of riboflavin. The RDA for riboflavin is about 1 mg, so maybe it should be 10 mg of riboflavin in each pill (which is the typical level in multi-vitamin B stress tablets).

 

I have a mulit-vitamin tablet weighing 0.849g. ... and I took 0.201g of the powder

So, you took 0.201 g of 0.849 g of a pill that has some amount of riboflavin in it. From here, you can calculate the mass you obtained, and then complete the concentration equation above.