Which of the followig statements about the spontaneous reaction occurring in a galvanic cell is always true?

Options

A. `E_(cell)^(@)lt0,triangleG^(@)0` and `QltK`
B. `E_(cell)^(@)gt0,triangleG^(@)lt0`, and `QgtK`
C. `E_(cell)^(@)gt0,triangleG^(@)gt0` and `QgtK`
D. `E_(cell)gt0,triangleGlt0` and `QltK`

Explanation

To determine which statement about the spontaneous reaction occurring in a galvanic cell is always true, we need to analyze the principles of electrochemistry, particularly focusing on the relationship between Gibbs free energy (ΔG), cell potential (E), and the reaction quotient (Q) and equilibrium constant (K).

### Step-by-Step Solution:

1. **Understanding Spontaneous Reactions**:
- A spontaneous reaction is one that occurs without the need for external energy. In electrochemistry, this means that the reaction can proceed in the forward direction naturally.

**Hint**: Recall the definition of spontaneous reactions and their characteristics.

2. **Gibbs Free Energy (ΔG)**:
- For a spontaneous reaction, the change in Gibbs free energy (ΔG) is always negative. This indicates that the process can occur without external energy input.

**Hint**: Remember that ΔG < 0 signifies spontaneity.

3. **Relationship Between ΔG and Cell Potential (E)**:
- The relationship between Gibbs free energy and cell potential is given by the equation:
\[ \Delta G = -nFE \]
where:
- \( n \) = number of moles of electrons transferred,
- \( F \) = Faraday's constant (approximately 96500 C/mol),
- \( E \) = cell potential (voltage).
- Since \( n \) and \( F \) are always positive, for ΔG to be negative, \( E \) must be positive.

**Hint**: Focus on the signs of ΔG and E in the equation.

4. **Equilibrium Constant (K) and Reaction Quotient (Q)**:
- The reaction quotient (Q) compares the concentrations of products and reactants at any point in the reaction. The equilibrium constant (K) is the value of Q at equilibrium.
- For a spontaneous reaction to occur, the condition \( Q < K \) must hold true, meaning the system is not at equilibrium and can proceed forward.

**Hint**: Think about how Q and K relate to the direction of the reaction.

5. **Conclusion**:
- Based on the analysis:
- ΔG is negative for spontaneous reactions.
- E is positive for spontaneous reactions.
- The relationship \( Q < K \) is true for spontaneous reactions.
- Therefore, the correct statement about spontaneous reactions in a galvanic cell is that the standard cell potential (E) is positive, and ΔG is negative.

### Final Answer:
The statement that is always true for spontaneous reactions occurring in a galvanic cell is that the standard cell potential (E) is positive, and Gibbs free energy (ΔG) is negative.