Which of the following are correctly matched?

Options

A. Schweitzer's reagent `rarr`An ammoniacal solution of cupric sulphate
B. Bordeaus mixture `rarr CuSO_(4)` and `Ca(OH)_(2)`
C. Semiconductor `rarr Ge`
D. Horn silver `rarr AgNO_(3)`

Explanation

To determine which of the given options are correctly matched, let's analyze each option one by one.

### Step 1: Analyze Option A
**Option A: Schweizer reagent and ammonical solution of cupric sulphate.**

- The Schweizer reagent is indeed an ammonical solution of cupric sulfate. It is represented by the formula Cu(NH3)4(H2O)2(OH)2.
- This confirms that Option A is correctly matched.

### Step 2: Analyze Option B
**Option B: Bordex mixture, copper sulphate plus Ca(OH)2.**

- The Bordex mixture is a combination of copper sulfate (CuSO4) and slaked lime (Ca(OH)2).
- This mixture is commonly used as a fungicide, confirming that Option B is also correctly matched.

### Step 3: Analyze Option C
**Option C: Semiconductor with germanium.**

- Germanium is indeed a semiconductor, which has conductivity between that of conductors and insulators.
- This confirms that Option C is correctly matched.

### Step 4: Analyze Option D
**Option D: Hone silver AgNO3.**

- The term "Hone silver" is incorrectly matched with AgNO3. The correct formula for hone silver is AgCl, which is silver chloride, not silver nitrate (AgNO3).
- Therefore, Option D is incorrectly matched.

### Conclusion
The correctly matched options are:
- Option A: Correct
- Option B: Correct
- Option C: Correct
- Option D: Incorrect

Thus, the correct options are A, B, and C.

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