Select the incorrect statements:

Options

A. `K_(p)` or `K_(c)` are dimenensionless if pressure or concentration are expressed in standard state.
B. The neumerical value of `K_(p)` changes with experimental conditions, i.e.P, T, and C at which equilibrium is attained.
C. Active mass of reactant = concentration of reactant
D. Dissolution of `NH_(3)` in water increases with increasing pressure.

Answer

To solve the question of selecting the incorrect statements regarding chemical equilibrium, we will analyze each statement one by one.

### Step 1: Analyze Statement A
**Statement A:** Kp or Kc are dimensionless if pressure or concentration are expressed in standard state.

**Analysis:** This statement is true. Kp and Kc are defined as the ratios of the concentrations or partial pressures of products to reactants, which are both expressed in the same units (e.g., atm for pressure or mol/L for concentration). Therefore, when these ratios are taken, the units cancel out, making Kp and Kc dimensionless.

### Step 2: Analyze Statement B
**Statement B:** The numerical value of Kp changes with experimental conditions that is pressure, temperature, and concentration at which equilibrium is attained.

**Analysis:** This statement is incorrect. The value of Kp is only affected by temperature. Changes in pressure and concentration do not affect the value of Kp; they only affect the position of equilibrium. Therefore, this statement is the incorrect one.

### Step 3: Analyze Statement C
**Statement C:** Active mass of a reactant is equal to the concentration of reactant.

**Analysis:** This statement is true. The active mass refers to the concentration of the reactant that is actually participating in the reaction. Therefore, this statement is correct.

### Step 4: Analyze Statement D
**Statement D:** Dissolution of NH3 in water increases with an increase in pressure.

**Analysis:** This statement is true. According to Le Chatelier's principle, increasing the pressure will favor the direction of the reaction that produces fewer moles of gas. Since NH3 gas dissolves in water to form fewer moles in solution, increasing the pressure will indeed increase the dissolution of NH3 in water.

### Conclusion
After analyzing all four statements, we find that the incorrect statement is **Statement B**.

### Summary of Incorrect Statement:
- **Incorrect Statement:** The numerical value of Kp changes with experimental conditions that is pressure, temperature, and concentration at which equilibrium is attained.

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