According to Henry's law, the partial pressure of gas `(p'_(g))` is directly proportional to mole fraction of gas in dissolved state, i.e., `P_("gas")'=K_(H),X_("gas")` where `K_(H)` is Henry's constant. Which are correct?

Options

A. `K_(H)` is characteristic constant for a given gas-solvent system
B. Higher is the value of `K_(H)`, lower is solubility of gas for a given partial pressure of gas
C. `K_(H)` has temperature dependence
D. `K_(H)` decreases with increase of tempreature

Answer

To solve the question regarding Henry's law and the characteristics of Henry's constant, we can break it down into a few steps:

### Step 1: Understand Henry's Law
Henry's law states that the partial pressure of a gas (P'_(g)) is directly proportional to the mole fraction of the gas in the dissolved state (X_(gas)). This relationship can be expressed mathematically as:
\[ P'_{gas} = K_H \cdot X_{gas} \]
where \( K_H \) is Henry's constant.

**Hint:** Remember that Henry's law is about the relationship between gas pressure and its concentration in a liquid.

### Step 2: Identify Characteristics of Henry's Constant
1. **Characteristic Constant**: Henry's constant \( K_H \) is specific to a particular gas-solvent system. This means that for a given gas in a specific solvent, \( K_H \) will have a unique value.
- **Correct Statement**: "Henry's constant is a characteristic constant for a given gas-solvent system."

2. **Solubility and Henry's Constant**: The higher the value of \( K_H \), the lower the solubility of the gas at a given partial pressure. This is because if \( K_H \) increases, the mole fraction \( X_{gas} \) must decrease to maintain the equality in the equation.
- **Correct Statement**: "Higher is the value of Henry's constant, lower is the solubility of a gas for a given partial pressure of gas."

### Step 3: Analyze Temperature Dependence
Henry's constant is influenced by temperature. Generally, as temperature increases, the solubility of gases in liquids decreases, which means that \( K_H \) increases with temperature.
- **Incorrect Statement**: "Henry's constant decreases with an increase in temperature." This is incorrect because \( K_H \) actually increases with temperature.

### Step 4: Summarize Correct Statements
From the analysis, the correct statements regarding Henry's law and Henry's constant are:
1. Henry's constant is a characteristic constant for a given gas-solvent system.
2. Higher the value of Henry's constant, lower the solubility of a gas for a given partial pressure of gas.
3. Henry's constant shows temperature dependence.

**Final Answer**: The correct statements are the first, second, and third.