Using the concentration of CH3COOH (0.8326M) and the equilibrium concentration of H3O+ (3.2x10-3), complete the reaction table for vinegar. Then calculate the acidity constant.
Reaction table is given
Ch3COOH + H2O --CH3COO- + H3O+
Initial.
Change
equilibrium
To complete the reaction table and calculate the acidity constant, you need to use the given information about the concentration of CH3COOH and H3O+ at equilibrium.
1. Fill in the "Initial" row of the reaction table:
- Initial concentration of CH3COOH: 0.8326 M
- Initial concentration of H2O: Since it is a solvent, its concentration remains constant and is not included in the table.
2. Determine the "Change" row of the reaction table:
- Change in concentration of CH3COOH: (-x), as CH3COOH is consumed during the reaction.
- Change in concentration of H2O: Doesn't change, as it is a solvent.
- Change in concentration of CH3COO-: (+x), as it is formed during the reaction.
- Change in concentration of H3O+: (+x), as it is formed during the reaction.
3. For the "Equilibrium" row of the reaction table:
- Concentration of CH3COOH: 0.8326 M - x
- Concentration of CH3COO-: x
- Concentration of H3O+: x
Now, we need to use the given equilibrium concentration of H3O+ (3.2x10^-3) to solve for x:
3.2x10^-3 = x
4. Solve the equation to find the value of x:
x = 3.2x10^-3
5. Substitute the value of x back into the equilibrium row to complete the table:
- Concentration of CH3COOH at equilibrium: 0.8326 M - 3.2x10^-3 M
- Concentration of CH3COO- at equilibrium: 3.2x10^-3 M
- Concentration of H3O+ at equilibrium: 3.2x10^-3 M
6. Finally, the acidity constant (Ka) can be calculated using the equilibrium concentrations of the species involved in the equation:
Ka = [CH3COO-][H3O+]/[CH3COOH]
Ka = (3.2x10^-3 M) * (3.2x10^-3 M) / (0.8326 M - 3.2x10^-3 M)
Simplify the expression to find the value of Ka.