Question
Give the pH of a strong base and an example:
Answers
GPT-4o mini
A strong base typically has a pH ranging from 12 to 14. This is because strong bases completely dissociate in water, resulting in a high concentration of hydroxide ions (OH⁻).
An example of a strong base is sodium hydroxide (NaOH). When dissolved in water, it dissociates completely:
\[ \text{NaOH} \rightarrow \text{Na}^+ + \text{OH}^- \]
If a 0.1 M solution of NaOH is prepared, the pH can be calculated as follows:
1. The concentration of hydroxide ions (OH⁻) from the dissociation of NaOH is 0.1 M.
2. Use the formula to find pOH:
\[ \text{pOH} = -\log[\text{OH}^-] = -\log[0.1] = 1 \]
3. Calculate pH using the relationship:
\[ \text{pH} + \text{pOH} = 14 \]
Thus,
\[ \text{pH} = 14 - \text{pOH} = 14 - 1 = 13 \]
Therefore, the pH of a 0.1 M NaOH solution would be around 13, indicating it is a strong base.
An example of a strong base is sodium hydroxide (NaOH). When dissolved in water, it dissociates completely:
\[ \text{NaOH} \rightarrow \text{Na}^+ + \text{OH}^- \]
If a 0.1 M solution of NaOH is prepared, the pH can be calculated as follows:
1. The concentration of hydroxide ions (OH⁻) from the dissociation of NaOH is 0.1 M.
2. Use the formula to find pOH:
\[ \text{pOH} = -\log[\text{OH}^-] = -\log[0.1] = 1 \]
3. Calculate pH using the relationship:
\[ \text{pH} + \text{pOH} = 14 \]
Thus,
\[ \text{pH} = 14 - \text{pOH} = 14 - 1 = 13 \]
Therefore, the pH of a 0.1 M NaOH solution would be around 13, indicating it is a strong base.