2. Calculate the initial concentration of Fe^3+, based on the dilution that resu

Question

2. Calculate the initial concentration of Fe^3+, based on the dilution that results from adding KSCN solution and water to the original 0.0020 M Fe(NO3)3 solution. See Step 5 of the procedure for the volume of each substance used in Trials 1-4. Calculate [Fe^3+]; using the equation: This should be the same for all four test tubes. 3. Calculate the initial concentration of SCN^-, based on its dilution by Fe(NO3)3 and water: In Test Tube 1. [SCN^-]; = (2 mL/ 10 mL)(.0020 M) = .00040 M Calculate this for the other test tubes.

Explanation / Answer

This both questions are actually pretty easy to solve, however you are not providing in question 2 or 3, the volume used of Fe(NO3)3 and the volume of KSCN used.

The equation you need to use it's the one that it's above in the questions, so with the data of volume for these 2 you just need to apply the equation and solve for innitial concentration.

Let's do some assumptios here, so you may have an idea of how to do it.

Let's suppose that you have the following volumes of Fe(NO3)3 used:

5 mL, 15 mL, 25 mL and 35 mL

and the total volume of dilution it's 50 mL

[Fe]i1 = 0.2 x (5/50) = 0.02 M

[Fe]i2 = 0.2 (15/50) = 0.06 M

[Fe]i3 = 0.2 (25/50) = 0.1 M

[Fe]i2 = 0.2 (35/50) = 0.14 M

With this procedure, you may actually go through question 2 and 3, but you need the actual data of volume of both of them. Provide those data and post it along with this question, in a new question if you want, and I'll gladly answer it for you. Hope this helps.

Related Questions

Navigate

• Browse (All)
• Browse 2
• Subjects

---

---

Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.