The total pressure of a mixture of two gases is:

Explanation

To solve the question regarding the total pressure of a mixture of two gases, we will apply Dalton's Law of Partial Pressures. Here’s a step-by-step solution:

### Step 1: Understand Dalton's Law of Partial Pressures
Dalton's Law states that in a mixture of non-reactive gases, the total pressure exerted by the mixture is equal to the sum of the partial pressures of each individual gas.

### Step 2: Define the Variables
Let:
- \( P_A \) = partial pressure of gas A
- \( P_B \) = partial pressure of gas B

### Step 3: Write the Equation
According to Dalton's Law, the total pressure \( P_{total} \) of the gas mixture can be expressed as:
\[ P_{total} = P_A + P_B \]

### Step 4: Conclusion
Thus, the total pressure of a mixture of two gases is the sum of the partial pressures of the individual gases.

### Final Answer
The total pressure of a mixture of two gases is given by:
\[ P_{total} = P_A + P_B \]

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