From your Dilution Data in the procedure 3 and 4, calculate the initial concentration of Fe3+ (aq) ion for tubes 2-5.

Question

1. Add 5.00ml of 1.00 x10^-3 M KSCN to all tubes.
2. To test tube 1 add 5 ml of 0.200M Fe(NO3)3.
3. Measure 8.00ml of 0.200M Fe(NO3)3 into 25.0ml cylinder. Fill to the 20ml mark with water. Add 5.00ml solution to tube 2. Save the remainder.
4. Pour 8.0ml solution in the beaker into 25.0ml cylinder. Fill to 20ml with water. Pour 5 ml solution into tube 3.
5. Repeat steps 4 and 5.

I don't understand the dilution to figure out the initial concentraions of Fe3+ of each one. Plz help.

Answer 1

2. You had 5 mL in the tube initially (of KSCN but that's still 5 mL). You add 5 mL of 0.2 M Fe(NO3)3 so the iron nitrate has been diluted from to 10 mL; therefore, its concentration has been halved. That is 0.2 M x (5/10) = ?
I'm assuming that the last sentence about adding 5.00 mL "solution" does NOT contain iron.

3. For this one you start with 0.2 M, and you go from 8 to 25. New concentration is 0.2 M x (8/25) = ?

4. I don't know what was in the beaker.
So far in 1,2,3 you've only talked about tubes and cylinders.