Dec . 11, 2024 07:35 Back to list

ph of 10m naoh

The pH of 10M NaOH Understanding Strong Bases and Their Effects

Sodium hydroxide (NaOH), commonly known as lye or caustic soda, is a highly soluble and strong base that plays a critical role in various chemical processes and industrial applications. One of the key characteristics of NaOH is its ability to dissociate completely in solution, which leads to an extremely high pH level, particularly when prepared in concentrated solutions. A 10M solution of NaOH is one such example where the pH is influenced by the concentration of hydroxide ions (OH⁻) present.

To understand the pH of a 10M NaOH solution, we first need to explore what pH means. The pH scale is a logarithmic scale used to specify the acidity or basicity of a solution. It typically ranges from 0 to 14, with values below 7 indicating acidity, 7 being neutral, and values above 7 denoting basicity. The pH is mathematically defined as the negative logarithm (base 10) of the hydrogen ion concentration [H⁺] in a solution.

In the case of a strong base like NaOH, when it dissolves in water, it dissociates completely into sodium ions (Na⁺) and hydroxide ions (OH⁻). The reaction can be represented as follows

\[ \text{NaOH (s)} \rightarrow \text{Na}^+ (aq) + \text{OH}^- (aq) \]

For a 10M NaOH solution, the concentration of OH⁻ ions is 10 moles per liter. To find the pH, we must first determine the pOH, which is the negative logarithm of the hydroxide ion concentration

\[ \text{pOH} = -\log [\text{OH}^-] = -\log(10) = -1 \]

ph of 10m naoh

According to the relationship between pH and pOH based on the water dissociation constant at 25°C

\[ \text{pH} + \text{pOH} = 14 \]

We can rearrange this equation to find the pH

\[ \text{pH} = 14 - \text{pOH} = 14 - (-1) = 15 \]

Therefore, the pH of a 10M NaOH solution is 15. This value indicates a highly alkaline solution, which is characteristic of strong bases. It is important to note that while the theoretical pH can exceed 14, common practice assumes a pH range of 0 to 14 for practical applications. However, a pH greater than 14 signifies a very concentrated basic solution.

Working with concentrated solutions of sodium hydroxide comes with safety considerations. The high pH means that even a small amount of NaOH can cause severe chemical burns upon contact with skin or mucous membranes. Therefore, proper protective equipment such as gloves, goggles, and lab coats should always be worn when handling it. Additionally, one should work in a well-ventilated area or use a fume hood to ensure safety from any potential fumes generated during mixing or other chemical reactions.

In conclusion, a 10M solution of NaOH showcases the properties of strong bases and their significantly high pH values. Understanding the implications of a high pH, as well as the handling requirements of such caustic substances, is essential for anyone working in chemical laboratories or industrial settings. The behavior of NaOH in solution not only serves as a fundamental concept in chemistry but also has practical applications across a wide range of industries, including manufacturing, food processing, and water treatment.

calcium ammonium nitrate fertiliser

cas 70693 62 8