Q&A Hero

Q: Which of the above molecules contains a carbonyl group? A) a B) all but a C) all but b D) c E) all but d

Q: The amino acid lysine is shown below. What functional group must be removed in order to produce cadaverine (1,5-pentanediamine)? A) One amino group must be removed and replaced with a hydrogen. B) The carboxyl group must be removed and replaced with a hydrogen. C) The hydrogen (shown) must be removed and replaced with an amino (NH2) group. D) Lysine is 1, 5-pentanediamine. Nothing has to be removed.

Q: If you saw the label "phenylephrine HCl" on a decongestant, would you worry that consuming it would expose you to the strong acid hydrochloric acid, HCl? A) No, because it is balanced by the phenylephrine. B) No, because the drug is in the solid phase. C) No, because this is a salt made using hydrogen chloride, but it is in no way hydrogen chloride. D) Yes, because of the hydrochloric acid it contains.

Q: In water, does the molecule lysergic acid diethylamide act as an acid, a base, neither or both? A) acid B) base C) neither an acid or a base D) both as an acid and as a base

Q: How many structural isomers are there for a compound having the molecular formula C3H9N? A) one B) two C) three D) four

Q: Alkaloid salts are not very soluble in the organic solvent diethyl ether. What might happen to the free-base form of caffeine dissolved in diethyl ether if gaseous hydrogen chloride, HCl, were bubbled into the solution? A) A second layer of water would form. B) Nothing, and the HCl gas would merely bubble out of solution. C) The diethyl ether insoluble caffeine salt would form as a white precipitate. D) The acid/base reaction would release heat, which would cause the diethyl ether to start evaporating.

Q: The solvent diethyl ether can be mixed with water but only by shaking the two liquids together. After the shaking is stopped, the liquids separate into two layers, much like oil and vinegar. The free-base form of the alkaloid caffeine is readily soluble in diethyl ether but not in water. Suggest what might happen to the caffeine of a caffeinated beverage if the beverage was first made alkaline with sodium hydroxide and then shaken with some diethyl ether. A) The water layer would turn a pink color indicating an alkaline pH. B) The caffeine would transform into the free base and transfer into the diethyl ether. C) The caffeine would transform into the free acid and transfer into the diethyl ether. D) The diethyl ether and water would mix into one layer.

Q: The phosphoric acid salt of caffeine has the structure: This molecule behaves as an acid in that it can donate a hydrogen ion, created from the hydrogen atom bonded to the positively charged nitrogen atom. What salt is formed when 1 mole of this salt reacts with 1 mole of sodium hydroxide, NaOH, a strong base? A) Salts can't react to form salts, rather they only arise from the reaction of an acid and a base. B) P- C) HP D) P

Q: A common inactive ingredient in products such as sunscreen lotions and shampoo is triethyl amine, also known as TEA. Which of the following is the chemical structure for this compound? (a) (b) (c) (d) A) a B) b C) c D) d

Q: Which of the following commonly acts as a base in chemical reactions? A) carboxylic acid B) alcohol C) ketone D) amine E) hydrocarbon

Q: Rank the following compounds by solubility in acidic water, from most soluble to least.1) CH3CH2OH 2) CH3OCH33) CH3CH2NH2A) 1, 3, 2B) 1, 2, 3C) 3, 2, 1D) 3, 1, 2E) 2, 1, 3

Q: Rank the following compounds by solubility in water, from most soluble to least.1) CH3CH2OH 2) CH3OCH3 3) CH3CH2NH2A) 1, 3, 2B) 1, 2, 3C) 3, 2, 1D) 3, 1, 2E) 2, 1, 3

Q: An amine can often form R-NH3+ (where R- can stand for anything) by reacting with water. What is happening? A) The amine is accepting a proton from the water molecule, forming OH-. B) Amines are basic. C) Amines are acidic. D) Amines can form H3O+ in water by donating a proton from the polar portion of the molecule. E) none of the above

Q: Which of the following compounds is an amine? A) a B) b C) c D) all of the above E) only b and c

Q: Which of the following molecules contains a phenol? A) a B) b C) c D) b and c E) all of them

Q: Why is 2,4,5-trifluorophenol much more acidic than phenol? A) The fluorines adjacent to the OH group are large and shield the hydroxl group from making the solution basic. B) The fluorines de-stabilize the benzene ring and thus give the structure more acidic characteristics. C) The fluorines have high electronegativities and help to stabilize the negative charges, which makes it even easier for the hydrogen to be lost. D) False! 2,4,5-trifluorophenol is actually not more acidic than phenol.

Q: One of the skin-irritating components of poison oak is tetrahydrourushiol: The long, nonpolar hydrocarbon tail embeds itself in a person's oily skin, where the molecule initiates an allergic response. Scratching the itch spreads tetrahydrourushiol molecules over a greater surface area, causing the zone of irritation to grow. Is this compound an alcohol or a phenol? A) an alcohol because of the hydroxyl groups it contains B) both a phenol and an alcohol because of the hydroxyl groups it contains C) a phenol because of the hydroxyl groups attached to the benzene ring D) neither an alcohol or phenol because it contains two hydroxyl groups instead of one

Q: How does ingested methanol lead to the damaging of a person's eyes? A) Eye tissues are soluble in methanol. B) The methanol is metabolized into formaldehyde, which is toxic to most living tissue. C) Methanol is very volatile. When brought close to the eyes, its vapors can harm the eyes. D) The methanol, once in the eyes, forms a crystalline precipitate that accumulates within the retina.

Q: What is the percent volume of water in 80-proof vodka? A) 80 percent B) 60 percent C) 40 percent D) 20 percent

Q: Why might a high-formula-mass alcohol be insoluble in water? A) A high formula mass alcohol would be too attracted to itself to be soluble in water. B) The bulk of a high formula mass alcohol likely consists of nonpolar hydrocarbons. C) Such an alcohol would likely be in a solid phase. D) In order for two substance to be soluble in each other their molecules need to be of comparable mass.

Q: Which of the following ethers has the highest boiling point? A) CH3OCH3 B) CH3CH2OCH2CH3 C) CH3CH2CH2OCH2CH2CH3 D) CH3CH2CH2CH2OCH2CH2CH2CH3

Q: Why do ethers have lower boiling points than that of an alcohol of the same molecular weight? A) Ethers cannot hydrogen bond to other ethers. B) Ethers do not have hydrogens. C) Ethers are more flammable and vaporize more easily. D) Ethers have higher boiling points than alcohols. E) all of the above

Q: The following picture shows an organic molecule: Which region (a-b-c) is a phenolic functional group? A) a B) b C) c D) b or c E) b and c

Q: Why is a phenol more acidic than a regular alcohol? A) Phenols have the ability to spread the negative charge that forms. B) Phenols have the ability to readily accept the positive charge of the proton. C) The negative charge is very concentrated on the oxygen ring of the phenol. D) The phenol has more negative charge and therefore is more stable. E) Phenols are not more acidic than a regular alcohol.

Q: Which of the following compounds is likely to have the best water solubility? A) CH3CH2OH B) CH3CH2CH2CH2OH C) CH3CH2CH2CH2CH2CH2OH D) CH3CH2CH2CH2CH2CH2CH2CH2OH

Q: If champagne has a proof of 28, how many milliliters of alcohol are in 250 mL of champagne? A) 35 B) 38 C) 28 D) 3.8 E) 200

Q: If an alcoholic beverage is 20 percent alcohol by volume, what is its proof? A) 40 proof B) 20 proof C) 10 proof D) Proof is a measure of flammability. E) Proof is a measure of the age of a fermented beverage.

Q: If an alcoholic beverage has a proof of 151, what is the percentage of alcohol in the beverage? A) 75.5 percent B) 151 percent C) 15.1 percent D) Proof is a measure of flammability. E) Proof is a measure of the age of a fermented beverage.

Q: Formaldehyde is a toxic preservative with the following chemical formula: H2CO Which of the following compounds would best serve as a starting point for its production? A) H3COH B) H2CCH2 C) H2O D) CH3CH2OH E) none of the above

Q: Correctly identify the following functional groups in this organic moleculeamide, ester, ketone, ether, alcohol, aldehyde, amine. A) 1 = ether, 3 = ester, 6 = aldehyde, 9 = alcohol B) 2 = amide, 4 = ester, 7 = amine, 8 = ether C) 1 = ester, 5 = alcohol, 8 = ether, 9 = ketone D) 2 = amide, 6 = aldehyde, 7 = amine, 8 = ether

Q: Heteroatoms make a difference in the physical and chemical properties of an organic molecule because A) they add extra mass to the hydrocarbon structure. B) each heteroatom has its own characteristic chemistry. C) they can enhance the polarity of the organic molecule. D) all of the above

Q: List the following compounds in order of least oxidized to most oxidized. A) a < b < c < d B) b < a < c < d C) c < d < a < b D) b < a < d < c

Q: What is a functional group? A) a set of atoms bonded together that give molecules containing them similar properties B) a group that adds function C) a group of hydrocarbons that can be used to make new materials D) a set of molecules that are grouped together to form a functional material E) none of the above

Q: Which of the following statements best describes the effect of heteroatoms on hydrocarbons? A) Heteroatoms greatly alter the chemical and physical properties of a hydrocarbon. B) Heteroatoms have little effect on the chemical and physical properties of a hydrocarbon. C) Heteroatoms have very similar properties to hydrocarbons. D) The properties of the heteroatom compounds depend only on the atom, not how it is bonded to the hydrocarbon. E) none of the above

Q: Which of the following is not a heteroatom? A) O B) N C) P D) A and B E) All of the above are heteroatoms.

Q: Which of the following is a heteroatom? A) O B) C C) H D) A and B E) all of the above

Q: Carbon-carbon single bonds can rotate while carbon-carbon double bonds cannot rotate. How many different structures are shown below. A) 1 B) 2 C) 3 D) 4

Q: Which of the above sections of this molecule would be considered to be the aromatic portion of the molecule?A) aB) bC) cD) a and bE) all of the above

Q: Which of the above sections of this molecule would be considered an unsaturated portion of the molecule?A) aB) bC) cD) a and bE) all of the above

Q: Which of the above sections of this molecule would be considered a saturated portion of the molecule?A) aB) bC) cD) a and bE) all of the above

Q: Which of the following is an aromatic molecule?A) aB) bC) cD) dE) all of the above

Q: Which of the following is not an unsaturated molecule? A) a B) b C) c D) d E) All of the above are unsaturated.

Q: Which of the following is a saturated molecule? A) a B) b C) c D) d E) none of the above

Q: Which of the following does not describe the number of other atoms a carbon atom can be bonded to? A) only 2 B) only 3 C) only 4 D) only 5

Q: Which of the following is the hallmark of a saturated hydrocarbon? A) a hydrocarbon where carbon has only a single bond to two or more other carbons B) a hydrocarbon that is completely dissolved in water C) a hydrocarbon where carbon has multiple bonds to one or more other carbons D) any molecule that is completely dissolved in a hydrocarbon solvent E) none of the above

Q: What is the chemical formula for the following structure? A) B) C) D)

Q: The temperatures in a fractionating tower at an oil refinery are important, but so are the pressures. Where might the pressure in a fractional distillation tower be greatest, at the bottom or at the top? Defend your answer. A) The pressure is greatest at the bottom because the higher temperature means a greater number of vaporized molecules. B) The pressure is greatest at the top because the higher temperature means a greater number of vaporized molecules. C) The pressure is greatest at the bottom because the lower temperature means a greater number of vaporized molecules. D) The pressure is greatest at the top because the lower temperature means a greater number of vaporized molecules.

Q: In a fractionating tower, the crude oil vapors pass from a pipe still into the column. Tar and lubricating stock are the first components to be pulled off at the bottom. Nearer the top kerosene is pulled off followed by gasoline and finally natural gas at the very top. From this information, which has a higher boiling point, gasoline or kerosine? A) Gasoline has the higher boiling point. B) Kerosene has the higher boiling point. C) Their boiling points are the same, but kerosene has the greater density. D) Fractional distillation components are pulled off based on molecular weight, so it is not possible to know which has the higher boiling point from the information given.

Q: Which two of these four structures are of the same structural isomer? A) upper right and lower left B) upper left and lower right C) lower left and upper right D) lower right and upper right

Q: How many structural isomers are shown here? A) one B) two C) three D) four

Q: Why does the melting point of hydrocarbons increase as the number of carbon atoms per molecule increases? A) An increase in the number of carbon atoms per molecules also means an increase in the density of the hydrocarbon. B) because of greater induced dipole-induced dipole molecular attractions C) Larger hydrocarbon chains tend to be branched. D) The molecular mass also increases.

Q: What property of carbon allows for the formation of so many different organic molecules? A) Carbon forms three different isotopes which allows for the formation of many more molecules than other elements. B) Carbon atoms are unique in their ability to form strong chemical bonds repeatedly with other carbon atoms, which permits the formation of countless possible structures. C) Carbon atoms uniquely contain exactly the same number (six) of protons, neutrons and electrons in their atomic structure. D) Carbon resides in the exact middle of the periodic table, from left to right, with exactly the same number of reactive elements on either side of it. It can therefore react with the maximum number of elements.

Q: What is indicated by a gasoline's octane rating? A) the degree of branching in the gasoline hydrocarbons B) the degree at which the compound ignites C) the percentage of octane in the mixture D) a measure of how many degrees it takes to ignite a mixture of octane E) none of the above

Q: Where would you expect to isolate molecules in a fractionating tower that have very few interatomic attractions? A) near the bottom B) near the top C) near the middle D) Fractional distillation takes advantage of molecular weight. E) Fractional distillation takes advantage of the number of isomers.

Q: Where would you expect to isolate molecules in a fractionating tower that have a large number of interatomic forces? A) near the bottom B) near the top C) near the middle D) Fractional distillation takes advantage of molecular weight. E) Fractional distillation takes advantage of the number of isomers.

Q: Which of the following molecules would probably be isolated closest to the bottom of a fractionating tower at a refinery? A) C4H10 B) C8H18 C) C10H22 D) C20H42 E) C40H82

Q: Which of the following molecules would probably be isolated closest to the top of a fractionating tower at a refinery? A) C4H10 B) C8H18 C) C10H22 D) C20H42 E) C40H82

Q: Upon combustion, about how many grams of water vapor are produced from every 16 grams of methane, ?+ 2 -> + 2 OA) 16 gramsB) 18 gramsC) 36 gramsD) 8 grams

Q: Why is the air over an open flame always moist? A) The hot flame vaporizes the water in the air above the flame. B) One of the products of combustion is water vapor. C) Warm air contains more humidity than cold air. D) None of the above is true.

Q: One of the products of combustion is water. Why doesn't this water extinguish the combustion? A) While areas of combustion are being extinguished, new areas are combusting. B) Combustion only produces micro amounts of water. C) The chemical combustion reaction is happening too fast for the water to have an effect on the fire. D) This water is in the gaseous phase and merely floats away from the fire.

Q: Copper atoms have a greater tendency to be reduced than iron atoms do. Was this good news or bad news for the Statue of Liberty, whose copper exterior was originally held together by steel rivets? A) This was good news since the steel rivets prevented the copper from eroding. B) Electrons will preferentially flow from the iron to the copper and then onto oxygen. Corrosion is thus accelerated around the interface of these two metals. C) This combination of metals have no effect on each other and that is why engineers chose to use them together. D) This combination of metals caused the copper to oxidize and turn green.

Q: Iron atoms have a greater tendency to oxidize than do copper atoms. Is this good news or bad news for a home in which much of the plumbing consists of iron and copper pipes connected together? Explain. A) This is bad news, since the iron atoms will be reduced by the copper atoms. B) This is not a problem, since the strength of the copper will make up for the weakness of the iron. C) It is bad news. The iron atoms will lose electrons to the copper atoms, which will pass those electrons onto oxygen atoms that are in contact with the surface. D) This is not a problem since any electrons lost will be replaced by copper electrons.

Q: Water is 88.88 percent oxygen by mass. Oxygen is exactly what a fire needs to grow brighter and stronger. So why doesn't a fire grow brighter and stronger when water is added to it? A) Oxygen in water is already "reduced" from the hydrogen atoms, so this oxygen atom no longer has a great attraction for additional electrons. B) The oxygen is chemically bound to hydrogen atoms. C) Oxygen in water is completely different from oxygen , which is what is required for combustion. D) all of the above

Q: Why are combustion reactions generally exothermic? A) Hydrogen easily pulls electrons from the oxygen in water molecules and are reduced. B) During combustion oxygen is oxidized, which gives off lots of energy. C) Combustion involves the transfer of electrons to oxygen, which has an extremely high tendency for gaining electrons. D) It is highly exothermic because combustion involves an oxidation-reduction reaction between a metallic material and oxygen.

Q: How many electrons are transferred from iron atoms to oxygen atoms in the formation of two molecules of iron hydroxide, Fe? A) 4 electrons B) 8 electrons C) 16 electrons D) 12 electrons

Q: The oxidation of iron to rust is a problem structural engineers need to be concerned about, but the oxidation of aluminum to aluminum oxide is not so much of a problem. Why? A) Since aluminum is so light and inexpensive, it is easily replaced when corroded. B) Aluminum oxide is insoluble in water and thus forms a protective coating that prevents continued oxidation of the aluminum. C) Aluminum oxide is even stronger than aluminum. D) The oxidation of aluminum is a very slow reaction, taking hundreds of years before any structural changes are noticed.

Q: A chemical equation for the combustion of propane, C3H8, is shown below. Through this reaction is the carbon oxidized or reduced? + 5 -> 3 + 4 OA) The carbon is oxidized.B) The carbon is reduced.C) Some of the carbons are oxidized while others are reduced.D) The carbon is neither oxidized nor reduced.

Q: Why is the formation of iron hydroxide, Fe, from and O not considered an oxidation-reduction reaction? A) The iron is only oxidized and nothing is reduced. B) The iron is only reduced, not oxidized. C) The ion is not changed during this chemical reaction. D) Iron can never be oxidized or reduced.

Q: How would connecting iron with a wire to a piece of metal like copper, which undergoes reduction very easily, affect the rate at which the iron corrodes? A) It would increase the rate of corrosion. B) It would decrease the rate of corrosion. C) The rate would stay the same. D) Rates are only affected by temperature. E) none of the above

Q: How does connecting a metal like iron with a wire to a metal that is easier to oxidize like zinc help prevent corrosion of the iron? A) The other metal is oxidized instead and the electrons travel to the iron, keeping it from oxidizing. B) The other metal absorbs the electrons from the iron, which keeps the iron from undergoing oxidation. C) The wire is acting as an oxidant and keeps the two metals from undergoing other chemical reactions. D) There is no salt-bridge, so there is no reaction between the two metals. E) The other metal is oxidized and adsorbs all the oxidant, keeping it away from the iron.

Q: Aluminum metal undergoes the same basic corrosion process that iron does yet it does not decompose as rapidly. Why? A) The aluminum oxide does not flake off like rust and acts as a protective layer. B) Aluminum is harder to oxidize than iron. C) Aluminum is harder to reduce than iron. D) The aluminum oxide product undergoes a reduction to produce aluminum metal. E) The aluminum is galvanized, which prevents oxidation.

Q: Rust has a tendency to form when iron in contact with water reacts according to the following reaction:4 Fe + 3 O2 -> 2 Fe2O3What is happening at the anodic region?A) Iron is being oxidized.B) Oxygen is being oxidized.C) Oxygen is being reduced.D) Iron is being reduced.E) none of the above

Q: Rust has a tendency to form when iron in contact with water reacts according to the following reaction:4 Fe + 3 O2 -> 2 Fe2O3What is happening at the cathodic region?A) Iron is being oxidized.B) Oxygen is being oxidized.C) Oxygen is being reduced.D) Iron is being reduced.E) none of the above

Q: Why is oxygen usually an oxidizing agent? A) It is a very electronegative element. B) It does not undergo reduction. C) It likes to be oxidized. D) It is very abundant and so it is easier to react than nitrogen. E) all of the above

Q: How might electrolysis be used to raise the hull of a sunken ship? A) An electric current passed through the hull of the ship would produce electrolysis and the gases trapped in the compartments of the vessel would push it upwards. B) The electrolysis of the water beneath the hull of the ship would boil the water and create upward pressure, thus buoying the ship upward. C) The gaseous products of the electrolysis of water could be collected with large bags attached to the hull of the ship. As the bags inflate with the gas they are buoyed upward pulling the ship also upward. D) Electrolysis could only be used to raise the hull of a ship if the ship were made of iron. If so, the electrolysis of the iron metal might produce enough gas to lift the ship.

Q: Jewelry is often manufactured by electroplating an expensive metal such as gold over a cheaper metal. A setup for this process can be sketched as follows: What would happen if the battery connections were suddenly reversed? A) The ring would continue to electroplate with gold. B) Gold ions in solution would get reduced and settle to the bottom of the container. C) Gold ions in solution would begin to electroplate onto the gold electrode. D) All electrolysis would stop.

Q: Sodium metal is A) oxidized in the production of aluminum. B) reduced in the production of aluminum. C) both oxidized and reduced in the production of aluminum. D) neither oxidized nor reduced in the production of aluminum.

Q: A major source of chlorine gas, , is from the electrolysis of brine, which is concentrated salt water, What is the sign of the electrode where the chlorine gas is formed? Is it negative or positive? A) Positive, since the chloride ions lose electrons to form chlorine molecules. B) Negative, since the chlorine gas needs to deposit electrons to form chloride ions. C) Neither, since chlorine gas is a neutral molecule, there is not electrode attraction. D) Both, since the chloride ions from NaCl (aq) are attracted to the positive electrode to form chlorine molecules while the produced chlorine gas molecules move to deposit electrons at the negative electrode.

Q: A major source of chlorine gas, , is from the electrolysis of brine, which is concentrated salt water, Which of the following is the balanced chemical reaction for this electrolysis reaction?A) NaCl (aq) + H2O -> NaOH (aq) + (g) + (g)B) 2 NaCl (aq) + O -> O (aq) + 2 HCl (aq)C) 2 NaCl (aq) + 2 O -> 2 Na (s) + O2 (g) + 2 (g) + (g)D) 2 NaCl (aq) + O -> 2 NaH (aq) + O- (aq)

Q: Why is recycling of aluminum better for the environment than electrolysis of bauxite (an aluminum ore)? A) It takes less energy to recycle aluminum. B) Electrolysis releases harmful gases into the atmosphere. C) The bauxite is extremely rare and there is very little aluminum in the world. D) Electricity is extremely cheap and it is better to use cheap electricity. E) none of the above