1) Write the complete and balanced equation for reaction of Calcium metal and a block of solid (P) \( \mathrm{Pa}_{4}^{+2} \mathrm{P}_{4}^{-3} \)

To write the **complete and balanced chemical equation** for the reaction between **calcium metal (Ca)** and a **block of solid phosphorus (P₄)**, we'll follow these steps: ### Step 1: Identify the Reactants and Products - **Reactants:** - **Calcium metal (Ca)** - **Phosphorus (P₄)**: Phosphorus commonly exists as P₄ molecules in its elemental form. - **Product:** - **Calcium Phosphide (Ca₃P₂)**: This is the typical product formed when calcium reacts with phosphorus. ### Step 2: Write the Unbalanced Equation \[ \text{Ca (s)} + \text{P}_4 \text{(s)} \rightarrow \text{Ca}_3\text{P}_2 \text{(s)} \] ### Step 3: Balance the Equation 1. **Calcium (Ca):** - There are **3 Ca atoms** in Ca₃P₂. - Therefore, we need **3 Ca atoms** on the reactant side. 2. **Phosphorus (P):** - There are **2 P atoms** in Ca₃P₂. - Since phosphorus is in the form of P₄, we'll need to adjust the coefficients accordingly. 3. **Balanced Equation:** \[ 6\, \text{Ca (s)} + \text{P}_4 \text{(s)} \rightarrow 2\, \text{Ca}_3\text{P}_2 \text{(s)} \] ### Final Balanced Equation \[ 6\, \text{Ca} (s) + \text{P}_4 (s) \rightarrow 2\, \text{Ca}_3\text{P}_2 (s) \] ### Explanation: - **6 Ca atoms** react with **1 P₄ molecule** to produce **2 units of Ca₃P₂**. - This ensures both **calcium** and **phosphorus** are balanced on both sides of the equation. ### Additional Notes: - **Calcium Phosphide (Ca₃P₂)** is commonly used in applications like pesticides, fungicides, and safety matches. - Always ensure to balance chemical equations to adhere to the **Law of Conservation of Mass**, which states that matter cannot be created or destroyed in a chemical reaction.