Which of the following element do not form complex with EDTA?

Options

A. Ca
B. Mg
C. Be
D. Sr

Answer

To determine which element does not form a complex with EDTA, we need to analyze the properties of EDTA and the elements in question.

### Step-by-Step Solution:

1. **Understanding EDTA**:
- EDTA stands for Ethylenediaminetetraacetic acid. It is a chelating agent that can form complexes with metal ions. EDTA has four negative charges and can bind to metal ions through its two amine groups and four carboxylate groups.

**Hint**: Remember that EDTA can form stable complexes with metal ions due to its ability to donate multiple pairs of electrons.

2. **Identifying the Elements**:
- The question mentions elements like magnesium, calcium, strontium, and beryllium. We need to evaluate which of these can form complexes with EDTA.

**Hint**: List the elements and recall their common oxidation states and coordination chemistry.

3. **Analyzing Each Element**:
- **Magnesium (Mg)**: Typically forms complexes with EDTA due to its +2 oxidation state.
- **Calcium (Ca)**: Also forms complexes with EDTA in its +2 oxidation state.
- **Strontium (Sr)**: Similar to magnesium and calcium, strontium can form complexes with EDTA.
- **Beryllium (Be)**: Beryllium has a small ionic radius and does not have vacant d-orbitals. It tends to form covalent bonds rather than coordinate complexes, making it less likely to form a stable complex with EDTA.

**Hint**: Consider the size and electronic configuration of the elements. Smaller ions may not form complexes as readily.

4. **Conclusion**:
- Among the elements listed, beryllium is the one that does not form a complex with EDTA due to its small size and lack of vacant d-orbitals.

**Final Answer**: Beryllium (Be) does not form a complex with EDTA.