How much electricity in terms of Faraday is required to produce 100 g of Ca from molten `CaCl_2` ?

Options

A. 1 F
B. 2 F
C. 3 F
D. 5 F

Explanation

To determine how much electricity in terms of Faraday is required to produce 100 g of calcium (Ca) from molten calcium chloride (CaCl₂), we can follow these steps:

### Step 1: Understand the reaction
Calcium ions (Ca²⁺) in molten calcium chloride need to be reduced to form calcium metal (Ca). The reduction half-reaction can be represented as:
\[ \text{Ca}^{2+} + 2e^- \rightarrow \text{Ca} \]
This indicates that 1 mole of calcium requires 2 moles of electrons (or 2 Faraday).

### Step 2: Calculate the moles of calcium to be produced
To find out how many moles of calcium correspond to 100 g, we use the molar mass of calcium, which is approximately 40 g/mol.
\[ \text{Moles of Ca} = \frac{\text{mass of Ca}}{\text{molar mass of Ca}} = \frac{100 \text{ g}}{40 \text{ g/mol}} = 2.5 \text{ moles} \]

### Step 3: Calculate the total Faraday required
Since 1 mole of calcium requires 2 Faraday, we can calculate the total Faraday required for 2.5 moles of calcium:
\[ \text{Total Faraday} = \text{moles of Ca} \times \text{Faraday per mole} = 2.5 \text{ moles} \times 2 \text{ Faraday/mole} = 5 \text{ Faraday} \]

### Conclusion
Thus, the total electricity required to produce 100 g of calcium from molten calcium chloride is **5 Faraday**.