QUIZBEE - Chapter 13

A 4.912-g sample of a petroleum product was burned in a tube furnace, and the SO₂ produced was collected in 3% H2O2. Reaction: SO₂(g) + H₂O₂ -> H₂SO₄

A 20.00-mL portion of 0.00873 M NaOH was introduced into the solution of H₂SO₄, following which the excess base was back-titrated with 15.17 mL of 0.01102 M HCl. Calculate the sulfur concentration in the sample in parts per million.

• 176.7 ppm S

• 166.7 ppm S

• 24.25 ppm S

• 24.52 ppm S

What do you call a compound whose purity has been determined
by chemical analysis? It serves as the working standard material for titrations and for many other analyses.

• Primary standard

• Secondary standard

• Ideal standard

• Indicator

A solution of HClO₄ was standardized by dissolving 0.4008 g of primary-standard-grade HgO in a solution of KBr: HgO(s) + 4Br^- + H₂O -> HgBr₄^2- + 2OH₂

The liberated OH₂ consumed 33.75 mL of the acid. Calculate the molar concentration of the HClO₄.

• 0.08549 M HClO4

• 0.10965 M HClO₄

• 0.08459 M HClO₄

• 0.10695 M HClO₄

What do you call this a process in which the excess of a standard solution used to consume an analyte is determined by titration with a second standard solution?

• Titration

• Back Titration

• Equivalence Point

• Standard Solution

What mass of solute in grams is contained in 2.50 L of a solution that contains 23.4 ppm

SnCl₂?

• 0.0558 g

• 0.0855 g

• 0.0585 g

• 0.00558 g

What do you call the point in a titration when a physical change occurs that is associated with the condition of chemical equivalence?

• Focal Point

• Equivalence Point

• End Point

• Game Point

A 0.5002-g sample that assayed 96.4% Na₂SO₄ required 48.63 mL of a barium chloride solution. Reaction: Ba²⁺ + SO₄²⁺ -> BaSO₄(s)

Calculate the analytical molar concentration of BaCl₂ in the solution.

• 0.0688 M

• 0.0698 M

• 0.0878 M

• 0.0887 M

The volume of a standard reagent is the measured quantity. What do you call this?

• coulometric titrations

• gravimetric titrations

• redox titrations

• volumetric titrations

What is the molar concentration of a solution that is 50.0% NaOH (w/w) and has a specific gravity of 1.52.

• 18.0 M

• 19.0 M

• 20.0 M

• 21.0 M

Describe the preparation of 1.50 L of a solution that is 12.0 ppm in K⁺, starting with solid K₄Fe(CN)₆.

• Dissolve 24.2. mg K₄Fe(CN)₆ in water and dilute to 1.50 L.

• Dissolve 44.2 mg K₄Fe(CN)₆ in water and dilute to 1.50 L.

• Dissolve 42.4 mg K₄Fe(CN)₆ in water and dilute to 1.50 L.

• Dissolve 22.4 mg K₄Fe(CN)₆ in water and dilute to 1.50 L.