What is the pH of a 0.1 M solution of ammonium chloride (NH4Cl)?
Practice Questions
Q1
What is the pH of a 0.1 M solution of ammonium chloride (NH4Cl)?
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5.5
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Questions & Step-by-Step Solutions
What is the pH of a 0.1 M solution of ammonium chloride (NH4Cl)?
Step 1: Identify the components of ammonium chloride (NH4Cl). It is made from ammonium (NH4+), which comes from a weak base (ammonia, NH3), and chloride (Cl-), which comes from a strong acid (hydrochloric acid, HCl).
Step 2: Understand that when NH4Cl dissolves in water, it dissociates into NH4+ and Cl-.
Step 3: Recognize that NH4+ can react with water (hydrolyze) to produce H+ ions and NH3. This reaction is: NH4+ + H2O ⇌ NH3 + H+. This means NH4+ can increase the concentration of H+ in the solution.
Step 4: Since H+ ions are produced, the solution will be acidic, which means the pH will be less than 7.
Step 5: Calculate the pH using the concentration of NH4+. For a 0.1 M solution, you can use the formula for pH: pH = -log[H+]. You will need to find the concentration of H+ produced from the hydrolysis.
Step 6: Use the equilibrium constant (Ka) for the reaction to find the concentration of H+. For NH4+, Ka can be derived from the Kb of NH3. Calculate the pH based on the concentration of H+.
