09 pre lab ka of an unknown acid - wofford...
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Determination of Ka for an Unknown Acid
0.699 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.60. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1006 M NaOH.
1. In the titration the initial volume of the buret was 5.91 mL and the final volume at the endpoint was 44.49 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 1 Name: ______________________________
Determination of Ka for an Unknown Acid
0.522 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 4.04. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0927 M NaOH.
1. In the titration the initial volume of the buret was 5.96 mL and the final volume at the endpoint was 35.60 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 2 Name: ______________________________
Determination of Ka for an Unknown Acid
0.509 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 2.95. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1002 M NaOH.
1. In the titration the initial volume of the buret was 6.44 mL and the final volume at the endpoint was 28.54 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 3 Name: ______________________________
Determination of Ka for an Unknown Acid
0.621 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 4.13. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1003 M NaOH.
1. In the titration the initial volume of the buret was 7.73 mL and the final volume at the endpoint was 42.16 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 4 Name: ______________________________
Determination of Ka for an Unknown Acid
0.570 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 2.71. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0979 M NaOH.
1. In the titration the initial volume of the buret was 3.16 mL and the final volume at the endpoint was 32.28 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 5 Name: ______________________________
Determination of Ka for an Unknown Acid
0.459 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.43. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1045 M NaOH.
1. In the titration the initial volume of the buret was 5.80 mL and the final volume at the endpoint was 27.77 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 6 Name: ______________________________
Determination of Ka for an Unknown Acid
0.502 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 4.68. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1036 M NaOH.
1. In the titration the initial volume of the buret was 5.52 mL and the final volume at the endpoint was 26.58 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 7 Name: ______________________________
Determination of Ka for an Unknown Acid
0.490 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.98. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1118 M NaOH.
1. In the titration the initial volume of the buret was 7.09 mL and the final volume at the endpoint was 27.02 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 8 Name: ______________________________
Determination of Ka for an Unknown Acid
0.442 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.75. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0952 M NaOH.
1. In the titration the initial volume of the buret was 5.94 mL and the final volume at the endpoint was 25.27 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 9 Name: ______________________________
Determination of Ka for an Unknown Acid
0.535 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 4.33. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0953 M NaOH.
1. In the titration the initial volume of the buret was 4.98 mL and the final volume at the endpoint was 28.39 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 10 Name: ______________________________
Determination of Ka for an Unknown Acid
0.660 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 4.30. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0963 M NaOH.
1. In the titration the initial volume of the buret was 7.92 mL and the final volume at the endpoint was 36.51 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 11 Name: ______________________________
Determination of Ka for an Unknown Acid
0.675 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.11. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0914 M NaOH.
1. In the titration the initial volume of the buret was 5.27 mL and the final volume at the endpoint was 42.16 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 12 Name: ______________________________
Determination of Ka for an Unknown Acid
0.593 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 2.92. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1034 M NaOH.
1. In the titration the initial volume of the buret was 3.87 mL and the final volume at the endpoint was 32.53 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 13 Name: ______________________________
Determination of Ka for an Unknown Acid
0.596 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.63. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1062 M NaOH.
1. In the titration the initial volume of the buret was 6.63 mL and the final volume at the endpoint was 32.15 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 14 Name: ______________________________
Determination of Ka for an Unknown Acid
0.672 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 2.89. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1037 M NaOH.
1. In the titration the initial volume of the buret was 4.35 mL and the final volume at the endpoint was 32.51 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 15 Name: ______________________________
Determination of Ka for an Unknown Acid
0.454 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 4.01. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1114 M NaOH.
1. In the titration the initial volume of the buret was 6.63 mL and the final volume at the endpoint was 23.63 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 16 Name: ______________________________
Determination of Ka for an Unknown Acid
0.671 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 2.75. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1101 M NaOH.
1. In the titration the initial volume of the buret was 6.46 mL and the final volume at the endpoint was 31.85 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 17 Name: ______________________________
Determination of Ka for an Unknown Acid
0.650 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.27. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1043 M NaOH.
1. In the titration the initial volume of the buret was 4.37 mL and the final volume at the endpoint was 39.00 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 18 Name: ______________________________
Determination of Ka for an Unknown Acid
0.400 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 2.81. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0968 M NaOH.
1. In the titration the initial volume of the buret was 3.17 mL and the final volume at the endpoint was 24.94 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 19 Name: ______________________________
Determination of Ka for an Unknown Acid
0.615 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 4.23. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1097 M NaOH.
1. In the titration the initial volume of the buret was 5.74 mL and the final volume at the endpoint was 32.45 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 20 Name: ______________________________
Determination of Ka for an Unknown Acid
0.558 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 2.84. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.0995 M NaOH.
1. In the titration the initial volume of the buret was 6.31 mL and the final volume at the endpoint was 34.38 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 21 Name: ______________________________
Determination of Ka for an Unknown Acid
0.533 grams of an unknown acid are added to a 400 mL beaker and dissolved in 100 mL of deionized
water. The pH of the solution is measured to be 3.98. After measuring the solution pH, three drops of the
phenolphthalein indicator are added to the solution. The solution is then titrated to a pink endpoint with
0.1086 M NaOH.
1. In the titration the initial volume of the buret was 7.01 mL and the final volume at the endpoint was 27.47 mL.
Determine the moles of acid titrated (recall moles OH−
= moles H+ at the equivalence point).
moles acid = ___________________________
2. Determine the molar mass of the acid.
Unknown acid molar mass = ___________________________
3. Use the pH to determine the [H+] in the initial 100 mL of H2O and from the molar mass of the acid
determine the [HA]0 in the 100 mL solution. From these two measurements calculate Ka for this weak
acid. You might want to construct an ICE table to help determine the expression for Ka.
Ka = _______________________________
Pre-Lab # 22 Name: ______________________________