Question
The following substances are considered "basic." Which one has the most disassociated "OH^- ions? Review U4L7 p. 2-4 (1 point) Responses Great Salt Lake, milk of magnesia pH 10 Great Salt Lake, milk of magnesia pH 10 Baking soda pH 9 Baking soda pH 9 Ammonia solution pH 11 Ammonia solution pH 11 Soapy Water pH 12
Answers
GPT-4o mini
To determine which substance has the most dissociated \( \text{OH}^- \) ions, we can look at the pH values provided. The pH scale ranges from 0 to 14, where lower values indicate acidic solutions and higher values indicate basic solutions. For basic solutions, as the pH increases, the concentration of hydroxide ions \( \text{OH}^- \) also increases.
The relationship between pH and the concentration of hydroxide ions is given by the formula:
\[
\text{pOH} = 14 - \text{pH}
\]
From this, we can calculate the pOH for each substance and determine the corresponding concentration of hydroxide ions:
1. **Great Salt Lake, milk of magnesia (pH 10)**:
- pOH = 14 - 10 = 4
- \([ \text{OH}^- ] = 10^{-4} \, \text{M}\)
2. **Baking soda (pH 9)**:
- pOH = 14 - 9 = 5
- \([ \text{OH}^- ] = 10^{-5} \, \text{M}\)
3. **Ammonia solution (pH 11)**:
- pOH = 14 - 11 = 3
- \([ \text{OH}^- ] = 10^{-3} \, \text{M}\)
4. **Soapy Water (pH 12)**:
- pOH = 14 - 12 = 2
- \([ \text{OH}^- ] = 10^{-2} \, \text{M}\)
Comparing the concentrations of \( \text{OH}^- \) ions:
- \( 10^{-4} \, \text{M} \) for Milk of Magnesia
- \( 10^{-5} \, \text{M} \) for Baking Soda
- \( 10^{-3} \, \text{M} \) for Ammonia
- \( 10^{-2} \, \text{M} \) for Soapy Water
Soapy Water, with a pH of 12, has the highest concentration of \( \text{OH}^- \) ions, making it the substance with the most disassociated \( \text{OH}^- \) ions.
**Answer: Soapy Water (pH 12)**
The relationship between pH and the concentration of hydroxide ions is given by the formula:
\[
\text{pOH} = 14 - \text{pH}
\]
From this, we can calculate the pOH for each substance and determine the corresponding concentration of hydroxide ions:
1. **Great Salt Lake, milk of magnesia (pH 10)**:
- pOH = 14 - 10 = 4
- \([ \text{OH}^- ] = 10^{-4} \, \text{M}\)
2. **Baking soda (pH 9)**:
- pOH = 14 - 9 = 5
- \([ \text{OH}^- ] = 10^{-5} \, \text{M}\)
3. **Ammonia solution (pH 11)**:
- pOH = 14 - 11 = 3
- \([ \text{OH}^- ] = 10^{-3} \, \text{M}\)
4. **Soapy Water (pH 12)**:
- pOH = 14 - 12 = 2
- \([ \text{OH}^- ] = 10^{-2} \, \text{M}\)
Comparing the concentrations of \( \text{OH}^- \) ions:
- \( 10^{-4} \, \text{M} \) for Milk of Magnesia
- \( 10^{-5} \, \text{M} \) for Baking Soda
- \( 10^{-3} \, \text{M} \) for Ammonia
- \( 10^{-2} \, \text{M} \) for Soapy Water
Soapy Water, with a pH of 12, has the highest concentration of \( \text{OH}^- \) ions, making it the substance with the most disassociated \( \text{OH}^- \) ions.
**Answer: Soapy Water (pH 12)**