Sort the following chromium compounds by whether the cation is chromium(II) or chromium(III). Cr2S3, Cr3P2, Crl3, CrO, CrBr2, CrN.

How would I solve this? Soo stuck. Thanks!
-MC

Well, MC, I'm not exactly a chemistry expert, but let me give it a shot!

To determine whether the cation is chromium(II) or chromium(III), we need to look at the oxidation state of chromium in each compound.

Let's break it down:

- Cr2S3: Considering that sulfur has an oxidation state of -2, and the entire compound has a neutral charge, each chromium atom must have an oxidation state of +3. So, chromium(III).
- Cr3P2: Since phosphorus usually has an oxidation state of -3, and the compound is neutral, each chromium atom must have an oxidation state of +2. Chromium(II).
- Crl3: This one is pretty straightforward. The Roman numeral indicates the oxidation state of chromium, so it's chromium(III).
- CrO: Oxygen usually has an oxidation state of -2, so chromium must have an oxidation state of +2. Chromium(II).
- CrBr2: Similar to CrO, each bromine atom has an oxidation state of -1, so chromium must have an oxidation state of +2. Chromium(II).
- CrN: Nitrogen typically has an oxidation state of -3, so chromium must have an oxidation state of +3. Chromium(III).

So, to summarize:

Chromium(II) compounds: Cr3P2, CrO, CrBr2.
Chromium(III) compounds: Cr2S3, Crl3, CrN.

I hope that helps! Just remember, chemistry can be confusing, but don't worry, you got this MC! Keep up the good work!

To determine whether the cation in the given chromium compounds is chromium(II) (Cr2+) or chromium(III) (Cr3+), you need to examine the oxidation states of chromium in each compound.

First, let's identify the oxidation states of chromium in the given compounds:

1. Cr2S3: Since sulfur (S) has an oxidation state of -2 and there are three sulfur atoms, the total oxidation state contributed by sulfur is -6. Since the overall charge of the compound is 0, the oxidation state of chromium (Cr) must be +6/2 = +3. Therefore, the cation is chromium(III) (Cr3+).

2. Cr3P2: Since phosphorus (P) has an oxidation state of -3 and there are two phosphorus atoms, the total oxidation state contributed by phosphorus is -6. Since the overall charge of the compound is 0, the oxidation state of chromium must be +6/3 = +2. Therefore, the cation is chromium(II) (Cr2+).

3. CrI3: In this compound, iodine (I) has an oxidation state of -1. Therefore, the chromium atom must have an oxidation state of +3 to neutralize the overall charge of 3-. Therefore, the cation is chromium(III) (Cr3+).

4. CrO: Oxygen (O) generally has an oxidation state of -2. However, in this case, chromium has an oxidation state of +2 since the compound is neutral and there is only one oxygen atom. Therefore, the cation is chromium(II) (Cr2+).

5. CrBr2: Bromine (Br) generally has an oxidation state of -1. In this compound, chromium is balanced with two bromine atoms, so to neutralize the overall charge, chromium must have an oxidation state of +2. Therefore, the cation is chromium(II) (Cr2+).

6. CrN: Nitrogen (N) generally has an oxidation state of -3. Chromium in this compound has an oxidation state of +3 to balance the overall charge. Therefore, the cation is chromium(III) (Cr3+).

So, based on the oxidation states identified, we can sort the chromium compounds as follows:

Cation Cr2+: Cr3P2, CrO, CrBr2
Cation Cr3+: Cr2S3, CrI3, CrN

To determine whether the cation in each chromium compound is chromium(II) or chromium(III), we need to determine the oxidation state of chromium in each compound.

The oxidation state of chromium can be obtained by assigning oxidation numbers to the elements in the compound and then solving for chromium. Here are the steps:

1. Start with compounds where you know the oxidation states of other elements:

- Cr2S3: The total charge of the compound is zero because Sulfur is -2, so each chromium atom must be in the +3 oxidation state. Therefore, Cr2S3 has chromium(III) cation.

- CrO: Oxygen is usually -2 in compounds, so we can assign it that oxidation state. The overall charge of CrO is zero, so the chromium atom must be in +2 oxidation state. Therefore, CrO has chromium(II) cation.

2. Use the oxidation states determined in step 1 to deduce the oxidation states of chromium in other compounds:

- Cr3P2: Phosphorus is usually -3 in compounds, so we can assign it that oxidation state. The overall charge of Cr3P2 is zero, so the three chromium atoms must balance out the -6 charge from two phosphorus atoms. Dividing the charge equally, each chromium atom will be in +2 oxidation state. Therefore, Cr3P2 has chromium(II) cation.

- CrI3: Iodine is usually -1 in compounds, so we can assign it that oxidation state. The overall charge of CrI3 is zero, so the three iodine atoms must balance out the -3 charge from the chromium atom. The chromium atom will be in +3 oxidation state. Therefore, CrI3 has chromium(III) cation.

- CrBr2: Bromine is usually -1 in compounds, so we can assign it that oxidation state. The overall charge of CrBr2 is zero, so the two bromine atoms must balance out the -2 charge from the chromium atom. The chromium atom will be in +2 oxidation state. Therefore, CrBr2 has chromium(II) cation.

- CrN: Usually, nitrogen has a -3 oxidation state in compounds. The overall charge of CrN is zero, so the nitrogen atom must balance out the -3 charge from the chromium atom. The chromium atom will be in +3 oxidation state. Therefore, CrN has chromium(III) cation.

So, after going through each compound, we can classify them based on the chromium cation as follows:

Chromium(II): CrO, CrBr2
Chromium(III): Cr2S3, Cr3P2, CrI3, CrN

One at a time. See Cr2S3.

How did it get that formula? I use the "cross charge" method which means Cr must be 3 and S must be 2.i ignore the charge of + and -; I figure the cation will be + and the anion will be -.

CrI3. Cr must be 3 and I must be 1.

This method won't work on 1:1 compounds like CrO. You know, however, that O is -2 so Cr must be +2.