Which of the following compounds are coloured due to charge transfer spectra?

Options

A. `K_(2)Cr_(2)O_(7)`
B. `H_(2)SO_(4)`
C. AgBr
D. `FeSO_(4)`

Answer

To determine which compounds are colored due to charge transfer spectra, we need to understand the concept of charge transfer and how it relates to the color of compounds.

### Step-by-Step Solution:

1. **Understanding Charge Transfer Spectra**:
- Charge transfer spectra occur when an electron moves from a ligand (like a halide ion) to a metal ion or vice versa. This transition can absorb light in the visible spectrum, leading to color in the compound.

2. **Identifying Compounds**:
- The question asks us to identify which compounds are colored due to charge transfer. Common examples of such compounds include transition metal complexes where ligands can donate electrons to the metal.

3. **Analyzing Given Compounds**:
- Let's analyze the compounds mentioned in the video transcript:
- **Chromium Compounds**:
- Chromium in the +6 oxidation state (e.g., CrO3) has no unpaired electrons in its d-orbitals (3d0 configuration), thus it does not show color due to d-d transitions but can show color due to charge transfer.
- **Silver Bromide (AgBr)**:
- This compound can show color due to charge transfer because of the polarization of the halogen.
- **Iron Compounds**:
- In FeSO4, iron is in the +2 oxidation state (3d6 configuration) with unpaired electrons, leading to color due to d-d transitions rather than charge transfer.

4. **Conclusion**:
- Based on the analysis, the compounds that exhibit color due to charge transfer spectra are:
- **Chromium compounds (in +6 state)**
- **Silver Bromide (AgBr)**

### Final Answer:
- The compounds that are colored due to charge transfer spectra are Chromium compounds in the +6 state and Silver Bromide (AgBr).