Which of the following has lowest reducing character ?

Options

A. `H_2O`
B. `H_2S`
C. `H_2Te`
D. `H_2Se`

Answer

To determine which of the given options has the lowest reducing character, we need to understand the concept of reducing agents. A reducing agent is a substance that donates electrons to another substance, causing the other substance to be reduced while itself gets oxidized. The strength of a reducing agent generally increases down a group in the periodic table due to the increase in atomic size and decrease in ionization energy.

### Step-by-Step Solution:

1. **Identify the Elements in Question**:
- Let's assume the options given are H2O, H2S, H2Se, and H2Te. These are hydrides of group 16 elements (chalcogens).

2. **Understand the Trend**:
- As we move down the group from oxygen (O) to tellurium (Te), the reducing character increases. This is because the bond strength between hydrogen and the chalcogen decreases down the group, making it easier for the hydrogen to donate electrons.

3. **Compare Reducing Characters**:
- H2O (water) has the strongest bond with hydrogen, making it a weak reducing agent.
- H2S (hydrogen sulfide) is a stronger reducing agent than H2O.
- H2Se (hydrogen selenide) is a stronger reducing agent than H2S.
- H2Te (hydrogen telluride) is the strongest reducing agent among these.

4. **Conclusion**:
- Therefore, H2O has the lowest reducing character among the given options.

### Final Answer:
The substance with the lowest reducing character is **H2O**.