The substance used in holmes singnals of the ship is a mixture of :

Options

A. `CaC_(2)+Ca_3P_2`
B. `Ca_3(PO_4)_2+Pb_3O_4`
C. `H_3PO_4+CaCl_2`
D. `NH_3+HOCl`

Answer

To solve the question regarding the substance used in Holmes signals of ships, we need to analyze the components involved and their reactions with water.

### Step-by-Step Solution:

1. **Identify the Components**: The question states that the substance used in Holmes signals is a mixture. The two substances involved are:
- Calcium carbide (CaC₂)
- Calcium phosphide (Ca₃P₂)

2. **Reactions with Water**:
- **Calcium Carbide Reaction**:
- When calcium carbide (CaC₂) reacts with water (H₂O), it produces:
\[ \text{CaC}_2 + 2\text{H}_2\text{O} \rightarrow \text{Ca(OH)}_2 + \text{C}_2\text{H}_2 \]
- This reaction yields calcium hydroxide (Ca(OH)₂) and acetylene gas (C₂H₂).

- **Calcium Phosphide Reaction**:
- When calcium phosphide (Ca₃P₂) reacts with water, it produces:
\[ \text{Ca}_3\text{P}_2 + 6\text{H}_2\text{O} \rightarrow 3\text{Ca(OH)}_2 + 2\text{PH}_3 \]
- This reaction yields calcium hydroxide (Ca(OH)₂) and phosphine gas (PH₃).

3. **Products of the Reactions**:
- From the reaction of calcium carbide, we obtain acetylene (C₂H₂), which is a flammable gas that can produce a bright flame.
- From the reaction of calcium phosphide, we obtain phosphine (PH₃), which is also a flammable gas.

4. **Function of the Gases**:
- Both acetylene and phosphine are used in signaling due to their ability to burn and produce light, which is essential for guiding ships.

5. **Conclusion**:
- The mixture of calcium carbide and calcium phosphide is used in Holmes signals of ships because it produces acetylene and phosphine when they react with water. Therefore, the correct answer to the question is that the substance used in Holmes signals is a mixture of calcium carbide (CaC₂) and calcium phosphide (Ca₃P₂).