Determine the pH for .16M of NaC2H3O2.
Determine the pH for .18M of NaCl.
NaC2H3O2 is sodium acetate. Let's call the acetate ion Ac^-.
Ac^- + HOH ==> HAc + OH^-
Kb = (Kw/Ka) = (HAc)(OH^-)/(Ac^-)
Set up an ICE chart and solve for OH^-, convert to H^+, then to pH.
To determine the pH of a solution, we need to consider the chemical properties of the solute and calculate the concentration of hydrogen ions (H+) present in the solution.
Let's first calculate the pH for a solution of 0.16 M NaC2H3O2, which is the sodium acetate.
Step 1: Identify the ions present in the solution.
NaC2H3O2 dissociates in water to form Na+ and C2H3O2- ions.
Step 2: Determine if the solute will undergo hydrolysis.
In this case, the C2H3O2- ion can react with water and accept a proton (H+) to form acetic acid (CH3COOH) and hydroxide ions (OH-). It is a basic hydrolysis reaction.
Step 3: Write down the hydrolysis reaction.
C2H3O2- + H2O ⇌ CH3COOH + OH-
Step 4: Calculate the concentration of hydroxide ions (OH-) resulting from hydrolysis.
Since the concentration of NaC2H3O2 is 0.16 M and sodium acetate completely dissociates, the concentration of C2H3O2- ions is also 0.16 M. However, the concentration of hydroxide ions is determined by the extent of hydrolysis. To simplify the calculation, we assume the reaction goes to completion. Therefore, the concentration of OH- is also 0.16 M.
Step 5: Calculate the concentration of hydrogen ions (H+).
Since water is neutral, the concentration of hydrogen ions (H+) must be equal to the concentration of hydroxide ions (OH-) for pH to be neutral (pH = 7). In this case, [H+] = 0.16 M.
Step 6: Calculate the pH.
The pH is calculated using the formula pH = -log[H+]. Therefore, pH = -log[0.16] ≈ 0.80.
So, the pH of a 0.16 M NaC2H3O2 solution is approximately 0.80.
Now, let's determine the pH of a solution of 0.18 M NaCl, which is sodium chloride.
Step 1: Identify the ions present in the solution.
NaCl dissociates in water to form Na+ and Cl- ions.
Step 2: Determine if the solute will undergo hydrolysis.
In this case, neither Na+ nor Cl- ions undergo hydrolysis as both are derived from strong electrolytes.
Step 3: Calculate the concentration of hydrogen ions (H+).
Since NaCl does not undergo hydrolysis and does not contribute any H+ or OH- ions to the solution, the concentration of hydrogen ions remains 0 M.
Step 4: Calculate the pH.
The pH is calculated using the formula pH = -log[H+]. Since [H+] is 0, the pH is undefined or 0.
Therefore, the pH of a 0.18 M NaCl solution is undefined or 0.