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1. Table showing equivalence points obtained from the graphs above for both the weak and strong acid
pH Graph (day 1) pH Graph (day 2) 1st derivative 2nd derivative Gran Plot
Strong acid 16.04 18.68 18.53 19.105 19.33
Weak acid 36.11 39.83 22.38 22.45 15.72
Sample calculation of Concentration of Acid
∗ Concentration of Strong Acid – HCl
2nd derivative
1dm3 NaOH = 0.0971M NaOH
19.105ml NaOH = 19.105ml/1000ml * 0.0971mole
= 1.8551 x 10-3 mole NaOH
1:1 mole ratio
25ml (pipetted) HCl = 1.8551 x 10-3 mole
1000ml HCl = (1000ml * 1.8551 x 10-3 mole)/25ml
= 0.074M HCl
∗ Concentration of Weak Acid – CH3COOH
2nd derivative
1dm3 NaOH = 0.0971M NaOH
22.45ml NaOH = 22.45ml/1000ml * 0.0971mole
= 2.1799 x 10-3 mole NaOH
1:1 mole ratio
25ml (pipetted) CH3COOH = 2.1799 x 10-3 mole
1000ml HCl = (1000ml * 2.1799 x 10-3 mole)/25ml
= 0.087M CH3COOH
Table Showing the Calculated Concentration of the Hydrochloric Acid and Acetic Acid Obtained
From the Average Concentration and Equivalence Volume of the Sodium Hydroxide
Ph Graph Ph Graph 1st Derivative 2nd Derivative Gran Plot
(Day 1) (Day 2)
[HCl] 0.062 0.073 0.072 0.074 0.075
[Acetic Acid] 0.140 0.155 0.087 0.087 0.061
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