What volume of 0.400 M Hg(NO3)2 is needed to precipitate all the I- ions from 250.0 mL of 0.300 M FeI3

There will be a follow-up questions so pay attention to my post!

Why don't you post all questions first, not many of use have the time to wait around to pay attention to your followon posts.

Didn't I answer this for you last night?

To determine the volume of 0.400 M Hg(NO3)2 needed to precipitate all the I- ions from 250.0 mL of 0.300 M FeI3, we need to consider the balanced chemical equation between Hg(NO3)2 and FeI3.

The balanced chemical equation is:
2 Hg(NO3)2 + 3 FeI3 → Hg2I2 + 6 Fe(NO3)3

According to the balanced equation, 2 moles of Hg(NO3)2 react with 3 moles of FeI3 to form 1 mole of Hg2I2. This means that the molar ratio between Hg(NO3)2 and FeI3 is 2:3.

First, let's calculate the number of moles of FeI3 in the initial solution:
Moles of FeI3 = Molarity × Volume (in liters)
Moles of FeI3 = 0.300 M × 0.250 L
Moles of FeI3 = 0.075 mol

Since the molar ratio between Hg(NO3)2 and FeI3 is 2:3, we can set up a proportion to find the number of moles of Hg(NO3)2 needed:
2 mol Hg(NO3)2 / 3 mol FeI3 = X mol Hg(NO3)2 / 0.075 mol FeI3

Simplifying the proportion:
2 / 3 = X / 0.075

To find X (the number of moles of Hg(NO3)2 needed), cross-multiply:
X = (2 / 3) × 0.075
X = 0.050 mol

Now, let's determine the volume of 0.400 M Hg(NO3)2 needed to obtain 0.050 mol:
Volume (in liters) = Moles / Molarity
Volume (in liters) = 0.050 mol / 0.400 M
Volume (in liters) = 0.125 L

Finally, convert the volume to milliliters (mL):
Volume (in mL) = Volume (in liters) × 1000
Volume (in mL) = 0.125 L × 1000
Volume (in mL) = 125 mL

Therefore, 125 mL of 0.400 M Hg(NO3)2 is needed to precipitate all the I- ions from 250.0 mL of 0.300 M FeI3.