Reaction Types - MCAT Biology
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In the human body, glycerol and three fatty acids can act together to form triacyl glycerol in a process known as esterification. The reverse of this process is known as __________.
In the human body, glycerol and three fatty acids can act together to form triacyl glycerol in a process known as esterification. The reverse of this process is known as __________.
When an alcohol and carboxylic acid are reacted together they can form an ester, in a process known as esterification. This is what happens with glycerol and fatty acids to form triacyl glycerol. The reverse of this process is an organic chemistry reaction known as saponification, in which an ester and water are reacted to form carboxylic acids and alcohol.
When an alcohol and carboxylic acid are reacted together they can form an ester, in a process known as esterification. This is what happens with glycerol and fatty acids to form triacyl glycerol. The reverse of this process is an organic chemistry reaction known as saponification, in which an ester and water are reacted to form carboxylic acids and alcohol.
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Which of the following is an example of an anabolic reaction in the body?
Which of the following is an example of an anabolic reaction in the body?
Anabolic reactions are reactions that construct molecules from smaller primary units. Catabolism is just the opposite, where larger molecules are degraded into simpler subunits. In the body larger macromolecules, such as proteins, are frequently created via condensation reactions. In condensation reactions, water is formed as a byproduct of joining two molecules together.
All other three processes describe a scenarios where a larger molecule is broken down into smaller subunits, known as catabolic processes.
Anabolic reactions are reactions that construct molecules from smaller primary units. Catabolism is just the opposite, where larger molecules are degraded into simpler subunits. In the body larger macromolecules, such as proteins, are frequently created via condensation reactions. In condensation reactions, water is formed as a byproduct of joining two molecules together.
All other three processes describe a scenarios where a larger molecule is broken down into smaller subunits, known as catabolic processes.
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Which of these methods can be used to synthesize a secondary alcohol?
Which of these methods can be used to synthesize a secondary alcohol?
All of these methods can successfully synthesize secondary alcohols.
Lithium aluminum hydride and sodium borohydride are strong and weaker reducing agents, respectively. Both are able to reduce ketones to secondary alcohols.
Adding water and acid to an alkene (such as propene) results in Markovnikov addition of a hydroxyl group, also creating a secondary alcohol.
Grignard reagents (organometallic halides) add to the carbonyl carbon of an aldehyde, adding an alkane group and forming an alcohol product.
All of these methods can successfully synthesize secondary alcohols.
Lithium aluminum hydride and sodium borohydride are strong and weaker reducing agents, respectively. Both are able to reduce ketones to secondary alcohols.
Adding water and acid to an alkene (such as propene) results in Markovnikov addition of a hydroxyl group, also creating a secondary alcohol.
Grignard reagents (organometallic halides) add to the carbonyl carbon of an aldehyde, adding an alkane group and forming an alcohol product.
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Drain cleaners a common household staple, used to open clogged drains in bathtubs and sinks. Human hair is a common culprit that clogs pipes, and hair is made predominately of protein. Drain cleaners are effective at breaking down proteins that have accumulated in plumbing. Drain cleaners can be either acidic or basic, and are also effective at breaking down fats that have accumulated with proteins.
A typical reaction—reaction 1—which would be expected for a drain cleaner on contact with human hair, would be as follows in an aqueous solution:
Another reaction that may occur, reaction 2, would take place as follows in an aqueous solution:
An alcohol reacts with the protein reactant in Reaction 2. Which atom in the protein reactant is likely to be the site of a nucleophilic attack?
Drain cleaners a common household staple, used to open clogged drains in bathtubs and sinks. Human hair is a common culprit that clogs pipes, and hair is made predominately of protein. Drain cleaners are effective at breaking down proteins that have accumulated in plumbing. Drain cleaners can be either acidic or basic, and are also effective at breaking down fats that have accumulated with proteins.
A typical reaction—reaction 1—which would be expected for a drain cleaner on contact with human hair, would be as follows in an aqueous solution:
Another reaction that may occur, reaction 2, would take place as follows in an aqueous solution:
An alcohol reacts with the protein reactant in Reaction 2. Which atom in the protein reactant is likely to be the site of a nucleophilic attack?
Carbonyl carbons bond with a strongly polar bond to the carbonyl oxygen. This strongly polar bond gives the carbon a partial positive charge, and thus makes it receptive to nucleophilic attack by other oxygens (e.g., alcohols).
Carbonyl carbons bond with a strongly polar bond to the carbonyl oxygen. This strongly polar bond gives the carbon a partial positive charge, and thus makes it receptive to nucleophilic attack by other oxygens (e.g., alcohols).
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Which of these is a dehydration synthesis reaction?
I. Formation of a disulfide bond between two cysteine residues
II. Carboxylation of a carbohydrate
III. Formation of an amide bond
IV. Splitting of dipeptides into amino acids
V. Addition of hydrogen to an unsaturated fatty acid
Which of these is a dehydration synthesis reaction?
I. Formation of a disulfide bond between two cysteine residues
II. Carboxylation of a carbohydrate
III. Formation of an amide bond
IV. Splitting of dipeptides into amino acids
V. Addition of hydrogen to an unsaturated fatty acid
Condensation reactions remove a small molecule—usually water—to bond two reactant molecules. In amide bonding, the carboxylic (–COOH, acid) portion of one amino acid is juxtaposed to the amide (–NH2, basic) end of a second amino acid. A molecule of water is extracted and the amide bond (–CONH) is formed. This is a variant of the classic statement, "Acid plus base yields salt plus water."
Technically, condensation reactions can remove small molecules other than water, but often the terms "condensation" and "dehydration" are used interchangeably in biochemistry (but not in organic chemistry). Incidentally, two cysteine molecules linked by a disulfide bond is renamed cystine (notice spelling alteration).
Condensation reactions remove a small molecule—usually water—to bond two reactant molecules. In amide bonding, the carboxylic (–COOH, acid) portion of one amino acid is juxtaposed to the amide (–NH2, basic) end of a second amino acid. A molecule of water is extracted and the amide bond (–CONH) is formed. This is a variant of the classic statement, "Acid plus base yields salt plus water."
Technically, condensation reactions can remove small molecules other than water, but often the terms "condensation" and "dehydration" are used interchangeably in biochemistry (but not in organic chemistry). Incidentally, two cysteine molecules linked by a disulfide bond is renamed cystine (notice spelling alteration).
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Which of the following is not capable of oxidizing a secondary alcohol to a ketone?
Which of the following is not capable of oxidizing a secondary alcohol to a ketone?
Lithium aluminum hydride is correct because it is a reducing agent, and is therefore not capable of oxidizing secondary alcohols. Instead, LAH could be used to perform the reverse reaction, reducing a ketone to an alcohol. The other answer choices are oxidizing agents.
Lithium aluminum hydride is correct because it is a reducing agent, and is therefore not capable of oxidizing secondary alcohols. Instead, LAH could be used to perform the reverse reaction, reducing a ketone to an alcohol. The other answer choices are oxidizing agents.
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Triacylglycerols are broken down in the body by lipases. In the presence of water, lipase is used to break down the triacylglycerol into a glycerol molecule and three fatty acids. Based on this information, the breakdown of a triacylglycerol is the opposite of which reaction?
Triacylglycerols are broken down in the body by lipases. In the presence of water, lipase is used to break down the triacylglycerol into a glycerol molecule and three fatty acids. Based on this information, the breakdown of a triacylglycerol is the opposite of which reaction?
The molecular structure of a triacylglycerol reveals that the three fatty acid tails are attached to the glycerol molecule, resulting in three ester functional groups. Remember that fatty acids have a carboxylic acid functional group at one end, which is created after the cleavage described in the question. Since the ester bonds are broken and carboxylic acids are created following the hydrolysis of a triglyceride, the opposite of esterification has taken place.
The process described (breakdown of an ester into a carboxylic acid) is also known as saponification.
The molecular structure of a triacylglycerol reveals that the three fatty acid tails are attached to the glycerol molecule, resulting in three ester functional groups. Remember that fatty acids have a carboxylic acid functional group at one end, which is created after the cleavage described in the question. Since the ester bonds are broken and carboxylic acids are created following the hydrolysis of a triglyceride, the opposite of esterification has taken place.
The process described (breakdown of an ester into a carboxylic acid) is also known as saponification.
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Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride 
in the proximal tubule of the kidney. When sodium is reabsorbed back into the blood, the molecule creates an electrical force. This electrical force then pulls water along with it into the blood. As more water enters the blood, the blood volume increase. By preventing the reabsorption of sodium, water reabsorption is reduced and the blood pressure decreases.
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more 
being expired. Based on Le Chatelier’s principle, the reaction will shift to the left. Since there is more bicarbonate than protons in the body, the blood will become more basic (respiratory alkalosis). To prevent such life threatening result, one would take a carbonic anhydrase inhibitor to prevent the reaction from shifting to the left.
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
A patient overdosed on an unknown drug. Two hours after being admitted into the hospital, acetazolamide was administered. A realtime measurement of the drug's concentration in the patient's blood was taken the moment the patient was admitted every 30 minutes. Which of the following best explains the lab results shown?
Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
A patient overdosed on an unknown drug. Two hours after being admitted into the hospital, acetazolamide was administered. A realtime measurement of the drug's concentration in the patient's blood was taken the moment the patient was admitted every 30 minutes. Which of the following best explains the lab results shown?
From the data, the concentration of the unknown drug in the blood increased shortly after the patient received the carbonic anhydrase inhibitor. The increase in the blood's concentration of the drug meant that the body is reabsorbing the drug. The only way for the drug to be reabsorbed is if it is able to cross the membrane of the renal's lumen. In order to cross the renal's membrane, the drug must be noncharged and nonpolar. Basic molecules in a basic environment will stay uncharged.
From the data, the concentration of the unknown drug in the blood increased shortly after the patient received the carbonic anhydrase inhibitor. The increase in the blood's concentration of the drug meant that the body is reabsorbing the drug. The only way for the drug to be reabsorbed is if it is able to cross the membrane of the renal's lumen. In order to cross the renal's membrane, the drug must be noncharged and nonpolar. Basic molecules in a basic environment will stay uncharged.
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Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride 
in the proximal tubule of the kidney. When sodium is reabsorbed back into the blood, the molecule creates an electrical force. This electrical force then pulls water along with it into the blood. As more water enters the blood, the blood volume increase. By preventing the reabsorption of sodium, water reabsorption is reduced and the blood pressure decreases.
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more being expired. Based on Le Chatelier’s principle, the reaction will shift to the left. Since there is more bicarbonate than protons in the body, the blood will become more basic (respiratory alkalosis). To prevent such life threatening result, one would take a carbonic anhydrase inhibitor to prevent the reaction from shifting to the left.
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
Glaucoma involves the pressure within the eye increasing to a dangerously high level due to improper draining of the vitreous humor. Blindness usually follows due to damage to the nerves. How might administering a carbonic anhydrase inhibitor help in patients with glaucoma?
Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
Glaucoma involves the pressure within the eye increasing to a dangerously high level due to improper draining of the vitreous humor. Blindness usually follows due to damage to the nerves. How might administering a carbonic anhydrase inhibitor help in patients with glaucoma?
From the equation:
We can see that carbonic anhydrase functions in both the forward and backward reactions. In the eye, the equation shifts to the left and more water is produced. Water is one of the main substances in vitreous humor. As the production of water increases, pressure increases as well. By blocking the production of water, the pressure is lowered.
From the equation:
We can see that carbonic anhydrase functions in both the forward and backward reactions. In the eye, the equation shifts to the left and more water is produced. Water is one of the main substances in vitreous humor. As the production of water increases, pressure increases as well. By blocking the production of water, the pressure is lowered.
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Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride 
in the proximal tubule of the kidney. When sodium is reabsorbed back into the blood, the molecule creates an electrical force. This electrical force then pulls water along with it into the blood. As more water enters the blood, the blood volume increase. By preventing the reabsorption of sodium, water reabsorption is reduced and the blood pressure decreases.
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more being expired. Based on Le Chatelier’s principle, the reaction will shift to the left. Since there is more bicarbonate than protons in the body, the blood will become more basic (respiratory alkalosis). To prevent such life threatening result, one would take a carbonic anhydrase inhibitor to prevent the reaction from shifting to the left.
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
When a patient is not ventilating efficiently, the kidneys try to compensate by producing more bicarbonate to buffer the decreasing pH of the blood due to the buildup of 
. Which of the following will increase the amount of 
in the blood?
I. Increase level in the blood
II. Increase 
level in the blood
III. Increase metabolism
Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
When a patient is not ventilating efficiently, the kidneys try to compensate by producing more bicarbonate to buffer the decreasing pH of the blood due to the buildup of
I. Increase
II. Increase
III. Increase metabolism
To answer this question, we must understand Le Chatelier’s principle. The reaction favorites the product when there is more of the reactants. The opposite is also true in that when there is a buildup of the products, the reaction will reverse and favorite the reactants. Increasing the metabolism will produce more , which will shift the equation to the right.
To answer this question, we must understand Le Chatelier’s principle. The reaction favorites the product when there is more of the reactants. The opposite is also true in that when there is a buildup of the products, the reaction will reverse and favorite the reactants. Increasing the metabolism will produce more
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Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride 
in the proximal tubule of the kidney. When sodium is reabsorbed back into the blood, the molecule creates an electrical force. This electrical force then pulls water along with it into the blood. As more water enters the blood, the blood volume increase. By preventing the reabsorption of sodium, water reabsorption is reduced and the blood pressure decreases.
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more being expired. Based on Le Chatelier’s principle, the reaction will shift to the left. Since there is more bicarbonate than protons in the body, the blood will become more basic (respiratory alkalosis). To prevent such life threatening result, one would take a carbonic anhydrase inhibitor to prevent the reaction from shifting to the left.
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
Based on the passage, which of the following statements, if true, will contradict the effectiveness of carbonic anhydrase inhibitors as a treatment?
Carbonic anhydrase is a very important enzyme that is utilized by the body. The enzyme catalyzes the following reaction:
A class of drugs that inhibits this enzyme is carbonic anhydrase inhibitors (eg. acetazolamide, brinzolamide, dorzolamide). These drugs are commonly prescribed in patients with glaucoma, hypertension, heart failure, high altitude sickness and for the treatment of basic drugs overdose.
In patients with hypertension, carbonic anhydrase inhibitors will prevent the reabsorption of sodium chloride
When mountain climbing, the atmospheric pressure is lowered as the altitude increases. As a result of less oxygen into the lungs, ventilation increases. From the equation above, hyperventilation will result in more
Carbonic anhydrase inhibitors are useful in patients with a drug overdose that is acidic. The lumen of the collecting tubule is nonpolar. Due to the lumen's characteristic, molecules that are also nonpolar and uncharged are able to cross the membrane and re-enter the circulatory system. Since carbonic anhydrase inhibitors alkalize the urine, acidic molecules stay in a charged state.
Based on the passage, which of the following statements, if true, will contradict the effectiveness of carbonic anhydrase inhibitors as a treatment?
Carbonic anhydrase inhibitors are used to alkalinize the urine. When the urine is alkalinized, acidic molecules will lose its proton and go into a charged state. Charged molecules are unable to cross the membrane of the lumen of the collecting tubule. Without the ability to cross the membrane, the molecule is therefore unable to be reabsorbed. Therefore, if the statement "Acidic molecules will not release its proton in the basic environment of the lumen of the collecting tubule" was true, then alkalinizing the urine will have no effect.
Carbonic anhydrase inhibitors are used to alkalinize the urine. When the urine is alkalinized, acidic molecules will lose its proton and go into a charged state. Charged molecules are unable to cross the membrane of the lumen of the collecting tubule. Without the ability to cross the membrane, the molecule is therefore unable to be reabsorbed. Therefore, if the statement "Acidic molecules will not release its proton in the basic environment of the lumen of the collecting tubule" was true, then alkalinizing the urine will have no effect.
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Compound B is dissolved in methylene chloride, and then treated with trifluoroacetic acid. Over the next thirty minutes, gas evolution was observed from the reaction mixture. What gas was being given off?
Compound B is dissolved in methylene chloride, and then treated with trifluoroacetic acid. Over the next thirty minutes, gas evolution was observed from the reaction mixture. What gas was being given off?
Treatment of a carboxylic acid with acid results in decarboxylation, and the evolution of 
, especially if the resulting compound contains a benzylic or allylic carbon, as is the case here.
Treatment of a carboxylic acid with acid results in decarboxylation, and the evolution of
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The combustion of pentane with oxygen gas is an exothermic reaction that produces carbon dioxide and water as products. Is this a spontaneous reaction?
The combustion of pentane with oxygen gas is an exothermic reaction that produces carbon dioxide and water as products. Is this a spontaneous reaction?
A balanced equation of the combustion of pentane indicates that one mole of pentane reacts with eight moles of oxygen gas to produce five moles of carbon dioxide and six moles of water.
Because there are nine moles of reactant and eleven moles of product, entropy increases in this reaction. Exothermic reactions that increase entropy are favorable at all temperatures, as seen in the Gibb's free energy equation.
In our scenario, H is negative and S is positive.
A balanced equation of the combustion of pentane indicates that one mole of pentane reacts with eight moles of oxygen gas to produce five moles of carbon dioxide and six moles of water.
Because there are nine moles of reactant and eleven moles of product, entropy increases in this reaction. Exothermic reactions that increase entropy are favorable at all temperatures, as seen in the Gibb's free energy equation.
In our scenario, H is negative and S is positive.
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Benzene
1,3,5-hexatriene
Which of the compounds shown above will have a greater heat of reduction (hydrogenation)?
Benzene
1,3,5-hexatriene
Which of the compounds shown above will have a greater heat of reduction (hydrogenation)?
The answer is 1,3,5-hexatriene. Chemicals that are more stable will give off less heat when they are reduced or hydrogenated. Although these two compounds contain the same number of pi bonds to be reduced, benzene is aromatic, and therefore is much more stable than the conjugated non-cyclic hexatriene. We would find that the heat of hydrogenation for hexatriene would be noticeably greater than that of benzene.
The answer is 1,3,5-hexatriene. Chemicals that are more stable will give off less heat when they are reduced or hydrogenated. Although these two compounds contain the same number of pi bonds to be reduced, benzene is aromatic, and therefore is much more stable than the conjugated non-cyclic hexatriene. We would find that the heat of hydrogenation for hexatriene would be noticeably greater than that of benzene.
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Alkenes A through D contain only carbon and hydrogen. They have the following heats of combustion at 
.
Alkene A: 
Alkene B: 
Alkene C: 
Alkene D: 
Rank these four alkenes in terms of their stability, with the least stable compound on the left, and the most stable compound on the right.
Alkenes A through D contain only carbon and hydrogen. They have the following heats of combustion at
Alkene A:
Alkene B:
Alkene C:
Alkene D:
Rank these four alkenes in terms of their stability, with the least stable compound on the left, and the most stable compound on the right.
A combustion reaction of any hydrocarbon yields the same products: carbon dioxide and water. The heat of combustion for the reaction shows how much energy is released as the hydrocarbon is converted to those products.
Since the products are the same for each alkene, any difference in heat of combustion will arise from differences in energy of the starting alkenes. Since the heat of combustion is negative, that means the reactants are higher in energy than the products, creating an exothermic reaction. Furthermore, the more negative the heat of combustion, the higher in energy the reactants are, and the less stable they are as well. Since compound D has the largest heat of combustion, it is highest in energy and therefore the least stable. By similar reasoning, B is the next highest in energy, followed by C, and then finally A, the most stable compound.
A combustion reaction of any hydrocarbon yields the same products: carbon dioxide and water. The heat of combustion for the reaction shows how much energy is released as the hydrocarbon is converted to those products.
Since the products are the same for each alkene, any difference in heat of combustion will arise from differences in energy of the starting alkenes. Since the heat of combustion is negative, that means the reactants are higher in energy than the products, creating an exothermic reaction. Furthermore, the more negative the heat of combustion, the higher in energy the reactants are, and the less stable they are as well. Since compound D has the largest heat of combustion, it is highest in energy and therefore the least stable. By similar reasoning, B is the next highest in energy, followed by C, and then finally A, the most stable compound.
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The most stable radical shown below is __________. The least stable radical shown below is __________.
The most stable radical shown below is __________. The least stable radical shown below is __________.
Radical stability increases as carbon substitution increases. In addition, radicals in conjugation with double bonds via resonance are more stable than the corresponding non-conjugated radical.
In this case radicals B, C, and D are all tertiary radicals, but only radical C has additional stabilization from resonance. Radical C is therefore the most stable. Radical E is the least substituted of the five radicals, and is the least stable.
Radical stability increases as carbon substitution increases. In addition, radicals in conjugation with double bonds via resonance are more stable than the corresponding non-conjugated radical.
In this case radicals B, C, and D are all tertiary radicals, but only radical C has additional stabilization from resonance. Radical C is therefore the most stable. Radical E is the least substituted of the five radicals, and is the least stable.
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Which of the following statements concerning the combustion of cycloalkanes is false?
Which of the following statements concerning the combustion of cycloalkanes is false?
The heat of combustion for cycloalkanes can be quantified based on two factors: the number of carbons in the ring, and the amount of strain in the ring. Cyclohexane does in fact have a larger molar heat of combustion than cyclobutane. This is because there are more carbons in the ring; however, ring stability will determine the heat of combustion per 
group in the ring. Even though cyclohexane has more carbons than cyclobutane, the heat of combustion per 
group in cyclobutane will be greater compared to cyclohexane due to cyclobutane's ring strain.
The heat of combustion for cycloalkanes can be quantified based on two factors: the number of carbons in the ring, and the amount of strain in the ring. Cyclohexane does in fact have a larger molar heat of combustion than cyclobutane. This is because there are more carbons in the ring; however, ring stability will determine the heat of combustion per
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What intermediate is involved in the conversion of compound B to compound C?
What intermediate is involved in the conversion of compound B to compound C?
The strong sulfuric acid protonates the hydroxyl group of compound B, resulting in the loss of water as a leaving group and the generation of a carbocation intermediate. Since this carbocation carbon is attached to three other carbons, this is a tertiary carbocation. It is bound to the phenyl substituent, a methyl group, and the branched carbon chain.
The strong sulfuric acid protonates the hydroxyl group of compound B, resulting in the loss of water as a leaving group and the generation of a carbocation intermediate. Since this carbocation carbon is attached to three other carbons, this is a tertiary carbocation. It is bound to the phenyl substituent, a methyl group, and the branched carbon chain.
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Consider the following radical bromination reaction of propane.
Which of the following substances would NOT be a suitable radical initiator for this reaction?
Consider the following radical bromination reaction of propane.
Which of the following substances would NOT be a suitable radical initiator for this reaction?
For any radical reaction, a suitable radical initiator is required. This either involves a chemical that decomposes to produce a radical upon heating, or ultraviolet light. For the former, any peroxide is suitable. AIBN also works, as it extrudes nitrogen upon heating to product a radical.
An ether, by contrast, will not produce a radical upon heating and would therefore not be a suitable radical initiator.
For any radical reaction, a suitable radical initiator is required. This either involves a chemical that decomposes to produce a radical upon heating, or ultraviolet light. For the former, any peroxide is suitable. AIBN also works, as it extrudes nitrogen upon heating to product a radical.
An ether, by contrast, will not produce a radical upon heating and would therefore not be a suitable radical initiator.
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Which of the compounds below could not be made from an aldehyde reduction?
Which of the compounds below could not be made from an aldehyde reduction?
Of the choices given, all can be made from some type of aldehyde reduction except choice II. Choices I, III, and IV each have the terminal (or primary) alcohol that is characteristic of a former aldehyde. In contrast, choice II has a secondary alcohol, characteristic of a former ketone. In other words, if choice II was oxidized then the product would be a ketone, not an aldehyde.
Of the choices given, all can be made from some type of aldehyde reduction except choice II. Choices I, III, and IV each have the terminal (or primary) alcohol that is characteristic of a former aldehyde. In contrast, choice II has a secondary alcohol, characteristic of a former ketone. In other words, if choice II was oxidized then the product would be a ketone, not an aldehyde.
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