Select the correct statement, for non stoichiometric cuprous oxide `Cu_(1.8)O`.

Options

A. a) `%` of `Cu^(2+)` in total copper is `11.11%`
B. b) `%` of `Cu^(1+)` in total copper is `11.11%`
C. c) It behaves like `p`-type semiconductor
D. d) Defect is metal deficiency defect

Explanation

To solve the question regarding the non-stoichiometric cuprous oxide `Cu_(1.8)O`, we will analyze the composition of the compound and determine the correct statements based on the information provided.

### Step-by-Step Solution:

1. **Identify the Composition of Cuprous Oxide**:
- The formula `Cu_(1.8)O` indicates that there are 1.8 copper (Cu) atoms for every oxygen (O) atom.

2. **Determine the Oxidation States**:
- In cuprous oxide, copper can exist in two oxidation states: Cu⁺ (cuprous) and Cu²⁺ (cupric).
- The oxidation state of oxygen is -2.

3. **Set Up the Charge Balance Equation**:
- Let the number of Cu⁺ ions be \( x \).
- Then the number of Cu²⁺ ions will be \( 1.8 - x \).
- The total positive charge must balance the negative charge from oxygen:
\[ x + 2(1.8 - x) - 2 = 0 \]

4. **Solve the Charge Balance Equation**:
- Rearranging the equation:
\[ x + 3.6 - 2x - 2 = 0 \]
\[ -x + 1.6 = 0 \implies x = 1.6 \]
- Therefore, the number of Cu⁺ ions is 1.6 and the number of Cu²⁺ ions is:
\[ 1.8 - 1.6 = 0.2 \]

5. **Calculate the Percentages**:
- **Percentage of Cu⁺ ions**:
\[ \text{Percentage of Cu}^+ = \left(\frac{1.6}{1.8}\right) \times 100 = 88.88\% \]
- **Percentage of Cu²⁺ ions**:
\[ \text{Percentage of Cu}^{2+} = \left(\frac{0.2}{1.8}\right) \times 100 = 11.11\% \]

6. **Evaluate the Statements**:
- **Option A**: Percentage of Cu²⁺ ions in total copper is 11.11% (Correct).
- **Option B**: Percentage of Cu⁺ ions in total copper is 11.11% (Incorrect, it is 88.88%).
- **Option C**: It behaves like a p-type semiconductor (Correct, due to the presence of holes from Cu²⁺).
- **Option D**: The defect is a metal deficiency defect (Correct, as it involves the loss of Cu atoms).

### Conclusion:
The correct statements are:
- A: Correct
- C: Correct
- D: Correct
- B: Incorrect