[kadaj]

S'up everyone,

If you are being provided with 1000 ppm Fe³⁺ solutions, how would you prepare a 30 ppm Fe³⁺ solution in two steps dilution?

Thank you

[sdekivit]

first i would suggest you make a 100 ppm solution and from the 100 ppm solution a 30 ppm solution.

[kadaj]

Ah ok, thank you, but is there any calculation required? 

[sdekivit]

you asked how you would prepare a solution in 2 steps and this is what i should do.

You can calculate the volumes needed to prepare both dilutions to prepare for example 100 mL 30 ppm solution.

[kadaj]

Thank you so much for that 

[AWK]

It depends on your possibility of volume measurement. The lowest error will be for dilution  abut 6 time twice, eg: dilute 20 ml to 100 ml (5 times), then 15 ml of the new solution to 100 ml (6,667 times) - that gives you dilution of 33.3333 times .
1000/33.3333=30 (needed concentration)

[kadaj]

Thank you for that, I was thinking of my lecturer possibly required me to do the calculation and then explain it using words

Thanks for the help