Analytical Chemistry Laboratory Quiz

__________ is the theoretical point in a titration analysis which indicates that the reaction is complete - that is, the number of moles of the titrant is equal to the number of moles of the analyte.

• End point

• Equivalence point

• Neutral point

• Initial point

• Buffer region

Which of the following types of titrations applies to an analyte that forms a slightly soluble salt with the titrant?

• Acid-base titration

• Complexometric titration

• Precipitation titration

• Redox titration

When carbon dioxide is present in the solution, the effective concentration of the base will ______.

• increase because more bicarbonate and carbonate ions will be formed

• decrease because the pH of the solution will increase

• increase because the pH of the solution will decrease

• decrease because the hydroxide ions will be consumed

• remain the same

The following statements regarding chemical indicators are true EXCEPT:

• Indicators are organic acids and bases.

• Indicators are very useful in visualizing the equivalence point of a titration analysis.

• Chemical indicators are added in minimal amounts.

• Indicators are substances that produce distinct colors at a certain pH.

• Indicators react with the first excess of the titrant.

Which of the following compounds is usually used when standardizing an acid titrant?

• Barium chloride

• Potassium hydrogen phthalate

• Sodium hydroxide

• Hydrochloric acid

• Tris-(hydroxymethyl)aminomethane

Tris-(hydroxymethyl)aminomethane (TRIS) is a______.

• Monoprotic acid

• Monoprotic base

• Diprotic acid

• Diprotic base

• Weak acid

Titration of a weak base against a weak acid results in ________.

• a neutral solution at pH = 7

• a poor titration curve (less defined equivalence point)

• a titration curve with two or more equivalence points

• a direct approach for qualitative and quantitative analysis of an analyte solution

• a color change from colorless to faint pink

An aqueous solution of potassium hydroxide is titrated with a 0.116 M solution of hydrochloric acid. If 22.9 mL of the acid are required to neutralize 24.0 mL of the base, what is the molarity of the potassium hydroxide solution? (2 points)

• 0.0553 M

• 0.211 M

• 0.111 M

• 0.122 M

• 0.221 M

An aqueous solution of hydrochloric acid is reacted with a 0.194 M solution of barium hydroxide. If 11.4 mL of the acid required 14.3 mL of the base to reach the endpoint, what is the molarity of the HCl solution? (2 points)

• 0.155 M

• 0.309 M

• 0.0773 M

• 0.122 M

• 0.487 M

What type of titration does the pH curve represent? (Format: Analyte-titrant titration)

• Strong monoprotic acid-strong base titration

• Strong monoprotic base-strong acid titration

• Weak monoprotic base-strong acid titration

• Strong diprotic acid-strong base titration

• Strong diprotic base-strong acid titration