We’re being asked to calculate the change in pH when 0.98 g of CH3COONa is added to 38 mL of 0.50 M acetic acid (CH3COOH) solution.
For this problem, follow these steps:
Step 1. Identify the conjugate base and weak acid
Step 2. Calculate the moles of weak acid
Step 3. Calculate the moles of conjugate base
Step 4. Calculate the pKa and pH
Step 1. The solution is composed of 0.50 M CH3COOH and 0.98 g CH3COONa .
▪ possess an H+ ion connected to a nonmetal (N) and oxygen → oxyacid
▪ have an equal number of oxygens than hydrogens → weak acid
Calculate the pH when 0.98 g of CH3COONa (FW = 82.03 g/mol) is added to 38 mL of 0.500 M acetic acid, CH3COOH. Ignore any changes in volume. The Ka value for CH3COOH is 1.8 x 10-5.
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