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Chemistry
Exam 3/ chapters 7 and 8
Question | Answer |
---|---|
Which is NOT a characteristic of acids? | taste bitter |
Lemon juice has a sour taste and turns litmus to red. Lemon juice is | acidic |
Which of the following acids is responsible for the sour taste of yogurt? | lactic |
Which of the following is/are characteristic(s) of bases? | taste bitter reacts with acids to form salts produce hydroxide ions when added to water |
A compound that changes color when it is placed into an acidic or a basic solution is | an acid-base indicator |
Which of the following is NOT true of the Arrhenius theory? | Acids are defined as compounds that produce OH- ions in water solution |
H3O+ is the | hydronium ion |
Which of the following is a correct definition of an acid that is not dependent upon the solvent? | acids are proton donors |
Sulfuric acid is the leading chemical produced and used industrially. What is the formula for sulfuric acid? | H2SO4 |
All of the following are bases EXCEPT A) KOH. B) HNO3. C) NH3. D) Ba(OH)2. | HNO3 |
A useful broad view of reactions between acids and bases involves the | transfer of protons |
A salt that can conduct electricity when it is dissolved in water is a(n) | electrolyte |
In what way are the green chemistry production of biodiesel fuel and of soap different? | Biodiesel fuels are converted to methyl esters, while soaps are converted to sodium salts |
When added to water, which of the following would produce a base? | Li2O |
Which of the following is an example of a nonmetal oxide? | SO2 |
When added to water, which of the following would produce an acid? | SO3 |
A nonmetal oxide is called a(n) | acidic anhydride |
Which is a weak base in aqueous solution? | NH3 |
The same number of moles of acetic acid and hydrogen chloride are placed in beakers containing water. After this addition, the beaker with the HCl has more hydronium ions than the beaker with added acetic acid. HCl is classified as | a stronger acid than acetic acid |
Hydroiodic acid is classified as a strong acid in water. This means that it produces | 100% of the maximum number of possible hydronium ions |
Ammonia is classified as a weak base in water. This means that it produces | a relatively small fraction of the maximum number of possible hydroxide ions |
When an aqueous solution containing hydrochloric acid is just neutralized with an aqueous solution containing sodium hydroxide, the solution would taste | salty |
Give an example of an amphiprotic compound | water |
In the balanced chemical reaction for the neutralization of calcium hydroxide with nitric acid, HNO3, the coefficient of nitric acid is | 2 |
Which of the following is the correct balanced equation for the neutralization of barium hydroxide with hydrochloric acid? | Ba(OH)2 + 2 HCl → BaCl2 + 2 H2O |
Phenolphthalein has often been used to monitor the progress of acid-base neutralization reactions. What color will phenolphthalein be if there is an excess of base present? | pink |
A sample of rainwater has a pH of 3.5. What ion is sure to be present in relatively large concentration in this rain sample? | H3O+ |
A solution with a pH of 3 has a hydronium ion concentration of | 10^-3 MOl/L |
If a solution has a pH of 6, what is the pOH? | 8 |
A solution with a pH of 12 will be | strongly basic |
An unknown substance is added to a solution and the pH increases. The substance is best described as a(n) | base |
Which substance has the lowest pH? A) urine B) lemon juice C) unpolluted rainwater D) 4% NaOH | lemon juice |
If the concentration of a dilute solution of potassium hydroxide is 0.001 M, what is the pH of that solution? | 11 |
Which of the following form a conjugate acid-base pair? | H2SO4 and HSO4- |
A conjugate acid-base pair differ by one | proton |
A mixture of a weak acid and its conjugate base forms a(n) | buffer |
Which of the following does NOT contribute to acid rain? | coal-burning power plants lightning volcanic eruptions |
Rain with which of the following pH of values would be considered to be acid rain? | 1.5 |
Sodium bicarbonate is commonly known as | baking soda |
Which antacid also acts as an antidiarrheal agent? | calcium carbonate |
When the pH of the blood is too high, the condition is called | alkalosis |
Hard water deposits (calcium carbonate) have built up around your bathroom sink. Which one of the following would be best to dissolve the deposit? | vinegar |
Another name for NaOH is | lye |
Lutefisk is a traditional Scandinavian food that is prepared by soaking a white fish, such as cod, in lye (NaOH). How does soaking the fish in lye "cook" it? | A strong base will break down or "denature" the protein in the fish |
Which of the following is a definition of reduction? | Reduction is the gain of hydrogen |
When C3H8 is burned in oxygen, the products are | CO2 + H2O |
In which of the following is the reactant undergoing oxidation? (Note: These reactions are not complete chemical equations.) | C → CO2 |
In which of the following is the reactant undergoing reduction? (Note: These reactions are not complete chemical equations.) | C2H4O → C2H6O |
Consider the following unbalanced equation between copper(I) ions and iron to produce copper metal and iron(II) ions: Cu+ + Fe → Cu + Fe2+ What is oxidized in this reaction? | Iron |
Every reduction reaction MUST be accompanied by | an oxidation reaction |
The black, granular material that fills a dry cell in a common flashlight (between the carbon rod and the zinc shell) is manganese(II) oxide, MnO2. The oxidation number of manganese in MnO2 is | +4 |
The oxidation number for l in l2 is | 0 |
Sodium bisulfite converts bromine (Br2) to bromide (Br-). Sodium bisulfite is a(n) | reducing agent. |
Which substance is an oxidizing agent? | H2O2 |
In the following reaction, hydrogen is the ________. CuO + H2 → Cu + H2O | reducing agent |
Copper is plated on zinc by immersing a piece of zinc into a solution containing copper(II) ions. In the plating reaction, copper II ions | gain two electrons and is are reduced |
Silver is plated on copper by immersing a piece of copper into a solution containing silver ions. In the plating reaction, copper | is oxidized and is the reducing agent |
An electrochemical cell is a device that converts chemical energy into | electrical energy |
A major advantage of lead storage batteries is that they are | rechargeable |
The small "button" cells used in hearing aids and hand calculators are being replaced by ________ cells. | zinc-air |
A substance that is reduced as a lead-acid storage battery generates an electric current is | PbO2 |
Consider the following reaction: 2 Fe + 3 Mg2+ → 2 Fe3+ + 3 Mg The half-reaction for the reduction in this reaction is | Mg2+ + 2 e- → Mg |
The removal of silver tarnish from silverware using aluminum foil and a solution of electrolyte is an example of | oxidation of aluminum metal. reduction of silver ions. an electrochemical cell |
Aluminum is more reactive than iron is, but iron corrodes more quickly. This occurs because | aluminum develops a coating of aluminum oxide, which protects it from further reaction |
Which of the following statements about the rusting of iron is true? | Iron is oxidized in the presence of oxygen |
Most chemical explosions are ________ reactions | oxidation-reduction |
________ is used as an explosive and a heart medication. | Nitroglycerin |
The most abundant element (by mass) in the human body is | oxygen |
When your car rusts, the major chemical reaction is that between the iron from the steel in the car body with the oxygen from the air to form iron(III) oxide. When the reaction is balanced, the coefficient of iron is | 4 |
This compound is a powerful oxidizing agent and a harmful pollutant; yet a layer of it in the upper stratosphere serves as a shield from harmful ultraviolet radiation from the sun. | O3 (ozone) |
Which of the following is NOT a common oxidizing agent? | an antioxidant |
Swimming pools are "chlorinated" in order to | disinfect the water |
Benzoyl peroxide, used in the treatment of acne, is | an oxidizing agent |
Oxidizing agents are often used | as antiseptics |
An oxidizing agent that was used in older versions of the Breathalyzer test is | K2Cr2O7 (potassium dichromate) |
Which substance is a common reducing agent used in the production of metals from ores? | Carbon |
The chemical basis of converting light into a photographic silver image is based on the fact that | Ag+ exposed to light is easier to reduce to Ag than unexposed Ag+. |
The "white" areas in a black-and-white "positive" print contain | no silver metal |
Which of the following is NOT true of a catalyst | A catalyst is used up when it catalyzes a reaction |
All of the following are reducing agents except | chlorine |
Antioxidants are | reducing agents found in foods |
Which of the following is NOT true of hydrogen? | It usually found as free hydrogen and not combined with other elements |
Human cells obtain energy by | oxidizing carbohydrates |
In the photosynthesis reaction: 6CO2 + 6H2O --> C6H12O6 + 6O2, the substance that serves as the reducing agent is | water |