General Chemistry
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A 35.0 mL of 0.225 M HCNO was titrated with 0.215 M KOH. Determine the volume of 0.215 M KOH necessary to reach the equivalence point. Calculate the pH after the addition of 85.0 mL of the base. The pKa for cyanic acid is 3.46.
The neutralization between acetic acid and nicotine has an equilibrium constant Kn of 1.8×103. What is the Kb for nicotine if the Ka for acetic acid is 1.8×10−5?
Hydroxylamine, HONH2, is a weak base used in the production of Nylon-6. Hydrocyanic acid, HCN, is a weak acid that is very poisonous. What is the Kn value for the neutralization reaction between hydroxylamine and hydrocyanic acid? Will the neutralization reaction go far into completion? (Ka HCN = 4.9×10−10, Kb HONH2 = 1.1×10−8)
A 75.0 mL of a 0.125 M solution of the protonated form of glycine was titrated with 12.5 mL of 0.125 M NaOH. Find the pH if the pKa values for the first and second dissociations are 2.34 and 9.78 respectively.
At the equivalence point, what is the pH for the titration of 0.15 M HClO and 0.15 M KOH? What is a suitable indicator for the titration? (Ka HClO = 3.0×10−8)
The following are representations of the initial concentrations of a weak acid HA (pKa = 6.15) and its potassium salt KA. Draw a representation of the equilibrium state of solution (4) upon the addition of 1 OH− ion. (The potassium ions and water molecules were omitted for clarity).
A 0.1164 g sample of an unknown monoprotic acid was dissolved in 35.0 mL of water. A 0.106 M KOH solution was used to titrate the resulting solution. A total of 17.8 mL of KOH was used to reach the equivalence point. The pH of the solution is 9.15 when 8.0 mL of the base was added. Calculate the Ka of the acid.
A 0.250 M KOH solution was used to titrate a 50.0 mL solution of 0.155 M hypochlorous acid (HClO, Ka = 3.0×10–8). Determine the resulting pH of the solution after 14.5 mL of KOH has been added.
What is the pH of the solution of 25 mL of 0.158 M nitrous acid titrated with 30 mL of 0.145 M NaOH?
What is the pH of the solution of 25 mL of 0.158 M benzoic acid titrated with 10 mL of 0.145 M NaOH?
At the equivalence point, what is the pH of the resultant solution obtained in a titration of 20.0 mL of 0.178 M acetic acid with 0.150 M NaOH?
What is the pH of 45.0 mL of 0.187 M ethanoic acid titrated with 0.00 mL of 0.200 M NaOH?
A solution is prepared by mixing 40 mL of 0.200 M acetic acid (CH3COOH) with 60 mL of 0.250 M potassium hydroxide (KOH). Calculate the pH of the solution.
A 30.0 mL sample of 0.150 M acetic acid solution is being titrated with 0.100 M NaOH solution. Calculate the pH of the solution after the addition of 30.0 mL of NaOH.
A 30.0 mL sample of 0.100 M benzoic acid (C6H5COOH) is titrated against 0.100 M NaOH. Calculate the pH of the solution at the endpoint. (Ka of benzoic acid = 6.31×10-5)
In the titration of 0.2011 g of an unknown monoprotic acid, 25.3 mL of 0.0650 M KOH solution was used to reach the endpoint. When the volume of the base added is 12.65 mL, the pH of the solution is 4.20. Determine the Ka for the acid.
Using mathematical proof, identify if the following statement is True or False: At the half-equivalence point of a titration of a weak acid with a strong base, the pH is equal to the pKa for the acid.
At the half-equivalence point, what is the pH of the titration of 20 mL of 0.178 M lactic acid with 0.150 M NaOH?
A 0.2850 g sample of an unknown monoprotic acid was dissolved in 30.0 mL of water. The resulting solution was titrated with 0.115 M KOH solution. Calculate the molar mass of the acid if a total of 27.5 mL of KOH was used to reach the equivalence point.
The molar mass of an unknown monoprotic acid was determined by titrating it with a 0.0650 M KOH solution. A 0.2011 g sample of the acid required 25.3 mL of the KOH solution to reach the endpoint. What is the molar mass of the acid?
The samples of chloric acid and formic acid shown below are both titrated with 0.75 M KOH. Does chloric acid need more KOH to reach the equivalence point than formic acid?
Potassium hydrogen phthalate (KHC8H4O4), abbreviated as KHP, is used for the standardization of bases used for titrations. The concentration of a lithium hydroxide solution was precisely determined by titrating 0.8585 g of KHP with the LiOH solution. A total of 19.63 mL of the LiOH solution was used to reach the equivalence point. Calculate the concentration of the LiOH solution.
Find the molar mass of the weak acid in the following scenario: A 2.50 mL solution of 3.00 M NaOH was mixed with a 6.51-g sample of a weak acid with Ka = 6.2 x 10-10. The resulting solution was diluted to 500.0 mL and was measured to have a pH of 7.72.
The equation for the reaction between nitrous acid and potassium hydroxide is
HNO2 + KOH → KNO2 + H2O
When 18.92 mL of HNO2 was titrated with 0.156 M KOH, 19.52 mL of KOH was required to reach the equivalence point. Calculate the mass of nitrous acid in grams present in a 1.00 qt sample
Determine the molar mass of a 0.1093 g weak monoprotic acid that is neutralized by titration of 9.86 mL of 0.1787 M KOH.
The titration of a 30.00-mL sample of HClO4 solution with an unknown concentration required 22.50 mL of 0.3520 M NaOH to reach the equivalence point according to the following reaction:
HClO4(aq) + NaOH(aq) → H2O(l) + NaClO4(aq)
Calculate the concentration of the HClO4 solution.
2.25 g of a monoprotic weak acid sodium bicarbonate (MW = 84.0 g/mol) was dissolved into water to make a homogenous solution that was titrated against a 0.800 M solution of potassium hydroxide (KOH). Calculate the volume (in mL) of the KOH solution required to reach the equivalence point?