Among the following, the non-spontaneous reaction is

Options

A. `ROH+R'MgX to R'H+Mg(OR)X`
B. `RONa+NH_(3) to NaNH_(2)+ROH`
C. `RON a+H_(2)O to NaOH+ROH`
D. `ROH+HC-=CN atoRON a+HC-=CH`

Explanation

To determine which of the given reactions is non-spontaneous, we need to analyze each option based on the strength of the acids and bases involved. Here’s a step-by-step breakdown:

### Step 1: Understand Spontaneity in Acid-Base Reactions
In acid-base reactions, a reaction is considered spontaneous if it moves from a weaker acid and a weaker base to a stronger acid and a stronger base. Conversely, if the reaction involves a stronger acid or base on one side, it may not proceed spontaneously.

**Hint:** Remember that the direction of an acid-base reaction favors the formation of the weaker acid and weaker base.

### Step 2: Analyze Each Option
1. **Option 1:** Reaction involving an alcohol and Grignard reagent (RMGX).
- Grignard reagents react with alcohols to form alkoxides (RO^-). Since alcohols (ROH) are generally weak acids, and Grignard reagents are strong bases, this reaction is spontaneous.

**Hint:** Identify the strength of acids and bases in the reaction to determine spontaneity.

2. **Option 2:** Reaction involving NH3 and ROH.
- Here, NH3 (ammonia) is a weak acid, and ROH (alcohol) is a stronger acid. Since the reaction is moving from a stronger acid (ROH) to a weaker acid (NH3), this reaction is non-spontaneous.

**Hint:** Compare the strengths of the acids and bases involved to see if the reaction favors the formation of weaker counterparts.

3. **Option 3:** Reaction involving NaOH and ROH.
- In this case, water (H2O) is a stronger acid compared to ROH. The reaction will proceed spontaneously as it moves from a weaker acid (ROH) to a stronger acid (H2O).

**Hint:** Look for the direction of the reaction based on the strength of acids and bases.

4. **Option 4:** Reaction involving acetylides and RO^-.
- Here, ROH is a strong acid compared to the alkyne (HC≡C^-), which is a weak acid. This reaction will also proceed spontaneously as it favors the formation of weaker acids.

**Hint:** Identify the stronger acid in the reaction to determine if the reaction will proceed spontaneously.

### Step 3: Conclusion
After analyzing all options, we conclude that the non-spontaneous reaction is **Option 2** (the reaction involving NH3 and ROH).

**Final Answer:** Option 2 is the correct answer.