Which pairs can not explain Dalton's law ?

Options

A. `H_(2), O_(2)`
B. `H_(2), F_(2)`
C. `NH_(3), HCl`
D. `NO, O_(2)`

Answer

To determine which pairs cannot explain Dalton's law of partial pressures, we need to understand the law itself. Dalton's law states that the total pressure of a mixture of non-reactive gases is equal to the sum of the partial pressures of each individual gas in the mixture. Therefore, if the gases in a pair are reactive and can undergo a chemical reaction, they cannot be used to explain Dalton's law.

### Step-by-Step Solution:

1. **Understanding Dalton's Law**:
- Dalton's law of partial pressures applies to mixtures of non-reactive gases. This means that the gases must not react with each other when mixed.

2. **Analyzing the Given Pairs**:
- **Pair 1: H2 and O2**:
- These gases do not react under normal conditions to form water (H2O) without an ignition source. Therefore, they can be considered non-reactive in this context and can explain Dalton's law.
- **Pair 2: H2 and F2**:
- This pair is reactive. When mixed, they react to form hydrogen fluoride (HF). Therefore, this pair cannot explain Dalton's law.
- **Pair 3: NH3 and HCl**:
- This pair is also reactive. They react to form ammonium chloride (NH4Cl). Thus, this pair cannot explain Dalton's law.
- **Pair 4: NO and O2**:
- These gases are reactive as well. They can react to form nitrogen dioxide (NO2). Therefore, this pair cannot explain Dalton's law.

3. **Conclusion**:
- The pairs that cannot explain Dalton's law of partial pressures are:
- H2 and F2
- NH3 and HCl
- NO and O2

### Final Answer:
The pairs that cannot explain Dalton's law are:
- H2F2 (H2 and F2)
- NH3 (NH3 and HCl)
- NO2 (NO and O2)