PPB

[destain]

One sample of potato, of mass 0.45g, was dissolved in acid, filtered and then made up to 10.0ml. The concentration of Cd2+ (aq) in the solution was found to be 3.5ppb.

a) Calculate the mass in ug of cadmium in the 10ml solution

b) Determine the concentration, in ppb, of cadmium in the sample of potato

[soccerboi]

Do you have the answers?

a)
=3.5X10^-9 mg/L
=3.5X10^-6 g/L
we want x g in 10ml so
x/ 3.5X10^-6  =  10/ 1000 (using ratios)
x= 3.5 X 10^-8 g in 10ml
  = 3.5X10^-5 mg in 10ml
  = 3.5X 10^-2 ug in 10ml

b)
=0.035ug in 10 ml
we want x ug in 1000ml
so using ratios  x/0.035=1000/10
x=3.5 ug in 1000ml
  = 3.5 ug in 1L
ppb is ng/L

so 3.5X10³ ng/L
thus 3500ppb

I'm not confident with my answers, but that's how i would do it

[destain]

part a is right and yeah i got that answer too but nope to part b, answer is 77.8ppb

[soccerboi]

3.5X 10^-2ug in 0.45g
we want x ug in 1000g

so using ratios, we get x= 77.8 but this is ppm, so i might have done something wrong...

[destain]

i'm not sure either...

but for now..
reaction between hex-1,6-diene and hydrogen bromide. number of structural isomers expected?
please explain