`pOH` water is `7.0at 298 K`. If water is heated to `350K`, which of the following should be ture?

Options

A. `pOH` will decrease
B. `pOH` will increase
C. `pOH` will remain seven
D. Concentration of `H^(o+)` ions will increae but that of `overset(Theta)OH` will decrease.

Explanation

To solve the problem, we need to analyze the behavior of water's ionization and the relationship between pOH, pH, and temperature.

### Step-by-Step Solution:

1. **Understanding pOH and Temperature**:
- At 298 K, the pOH of pure water is 7. This means that the concentration of hydroxide ions [OH⁻] is 10⁻⁷ M. Since water is neutral, the concentration of hydrogen ions [H⁺] is also 10⁻⁷ M.

2. **Effect of Temperature on Ionization**:
- When water is heated to 350 K, the dissociation of water increases. This means that more water molecules will dissociate into H⁺ and OH⁻ ions.

3. **Ionic Product of Water (Kw)**:
- The ionic product of water (Kw) is given by the equation:
\[ K_w = [H^+][OH^-] \]
- As temperature increases, Kw also increases. This means that both [H⁺] and [OH⁻] concentrations will increase, but they will remain equal in pure water.

4. **Calculating pOH**:
- pOH is calculated using the formula:
\[ pOH = -\log[OH^-] \]
- Since the concentration of OH⁻ increases with temperature, the pOH will decrease.

5. **Conclusion**:
- Therefore, as the temperature increases from 298 K to 350 K, the pOH of water will decrease due to the increase in the concentration of OH⁻ ions.

### Final Answer:
The correct statement is that the pOH will **decrease** when water is heated to 350 K.