Exam 4: Solution Chemistry: The Hydrosphere

Groundwater often has low levels of dissolved oxygen because it is not continually exposed to the atmosphere. When groundwater reaches the surface, the following reaction involving soluble iron(II) can occur. What are the oxidation numbers of the elements in the product, Fe(OH)₃? 4Fe²⁺(aq) O₂(g) 2H₂O(l ) 8OH^- 4Fe(OH)₃(s)

Which of the following ionic compounds is insoluble in water?

What is the molar concentration of sodium in a 200.0 mL solution prepared from 1.223 g of sodium phosphate (Na₃PO₄, 163.9 g/mol), which is a cleaning agent, food additive, and stain remover?

In a demonstration of strong electrolytes, weak electrolytes, and nonelectrolytes, Professor Popsnorkle used a lightbulb apparatus that showed how much a solution conducted electricity by the brightness of the lightbulb. When pure water was tested, the bulb did not light. When some acetic acid was added to the water, the bulb burned dimly. When more acetic acid was added to the solution, the bulb burned a little more brightly. In his frustration to make the bulb shine brightly with acetic acid, Professor Popsnorkle started over by testing the beaker of the pure acetic acid. What was the result?

Hartmann's solution is used in intravenous therapy to replace lost body fluid and mineral salts. Hartmann's solution contains 5.00 mM potassium chloride, 2.00 mM calcium chloride, and 102 mM sodium chloride. What is the total chloride ion concentration in Hartmann's solution?

When the oxidation reduction reaction shown here is balanced, how many electrons are transferred for each atom of copper that reacts? Ag⁺(aq) Cu(s) Ag(s) Cu²⁺(aq)

What volume of 12 M HCl solution needs to be diluted to produce 275 mL of 2.1 M HCl solution?

Based on the activity series shown below, which of the following statements is true?

Controlling the ammonia and ammonium ion concentrations is one of the biggest problems in maintaining a healthy fish aquarium. Ammonia, which is highly toxic to fish because it interferes with their uptake of oxygen, is formed from wastes excreted by the fish, uneaten food, and decaying plants. Beneficial bacteria oxidize the ammonia and ammonium to nitrate, which is not highly toxic to fish in low to moderate levels. Complete and balance the following reaction equation describing the oxidation of ammonium to nitrate ions in acidic solution. NH₄⁺(aq) + O₂(aq) NO₃^-

A 500 mg dietary supplement of L-lysine (an amino acid, 146.2 g/mol) required 68.4 mL of 0.100 M NaOH to reach the end point. How many protons were removed for each L-lysine molecule in this titration?

What volume of a 12 M KOH solution needs to be diluted to produce 475 mL of 3.1 M KOH solution?

Ammonia (NH₃) is a weak base that reacts with a strong acid to form the ammonium ion, NH₄⁺. If 5.00 mL of a solution of an ammonia cleaner is titrated directly with 42.6 mL of 0.5000 M HCl, what is the concentration of the NH₃ in solution? (Assume that the ammonia is the only solute that reacts with the acid.)

Which one of the following is not a polyprotic acid?

What is the oxidation number of S in H₂SO₄?

Which picture best represents an atomic-level view of a strong electrolyte solution (water molecules not shown)?

According to the label on a bottle of concentrated hydrochloric acid, the contents are 35% HCl by mass and have a density of 1.2 g/mL. What is the molarity of commercial concentrated hydrochloric acid?

Ion-exchange resins can remove Mg²⁺ and Ca²⁺0 in water (called softening) by releasing Na⁺. What would be the concentration of sodium ion in the softened water if the combined concentration of these Group 2A ions that were removed from the hard water was 0.026 M ?

A reaction that takes place between dissolved barium nitrate and dissolved sodium sulfate results in formation of solid barium sulfate. Which equation describes this reaction?

Concentrated sulfuric acid contains 4 g of water for every 100 g of solution. The solvent is ________

The oxidation number of carbon in carbon dioxide is ________