Chem 2004 Post Lab Discussion 3 PDF

Chem 2004 Post Lab Discussion 3 Answers 1. What is the product of oxidizing an aldehyde? A. Alcohol B. Alkane C. Carboxylic acid D. Ketone Answer: Carboxylic acid (C) Aldehydes are oxidized to carboxylic acids. 2. The oxidation product of formaldehyde is methanol. A. True B....

Chem 2004 Post Lab Discussion 3 Answers 1. What is the product of oxidizing an aldehyde? A. Alcohol B. Alkane C. Carboxylic acid D. Ketone Answer: Carboxylic acid (C) Aldehydes are oxidized to carboxylic acids. 2. The oxidation product of formaldehyde is methanol. A. True B. False Answer: False (B) The oxidation product of formaldehyde is formic acid, not methanol. 3. What functional group characterizes carboxylic acids? Answer: Carboxyl group (COOH) The carboxyl group is responsible for the properties of carboxylic acids. 4. Aldehydes can be distinguished from ketones by using.................................................. tests. Answer: oxidation Oxidation tests specifically target aldehydes to differentiate them from ketones. 5. Match the following organic compounds to their common characteristics: 1. Carboxylic A. Sweet-smelling colorless liquids acids 2. Acid B. Strong-smelling colorless liquids halides 3. C. Neutral solids Amides 4. D. Colorless liquids with sharp odors Esters Answer: Carboxylic acids = Colorless liquids with sharp odors Acid halides = Strong-smelling colorless liquids Esters = Sweet-smelling colorless liquids Amides = Neutral solids 6. What is the outcome of Tollen’s test with formaldehyde? A. Formation of white crystals B. Red precipitate of Cu2O C. No reaction D. Formation of silver metal Answer: Formation of silver metal (D) Tollen’s test reduces Ag(NH3)2OH to form silver metal when reacting with formaldehyde. 7. Carboxylic acids are typically soluble in water due to their high polarity. A. True B. False Answer: True (A) The carboxyl group makes carboxylic acids highly polar, enhancing their solubility in water. 8. Name a property of acid anhydrides. Answer: Strong-smelling colorless liquids Acid anhydrides share similar properties with acid halides, often being strong- smelling. 9. Which alcohol reacts the fastest in the Lucas Reaction? A. No alcohol reacts B. tert-Butyl alcohol C. Isopropyl alcohol D. Ethyl alcohol Answer: tert-Butyl alcohol (B) Tertiary butyl alcohol reacts fastest due to the stability of the corresponding tert-butyl carbocation. 10. Benzene reacts readily with oxidizing agents. A. True B. False Answer: False (B) Benzene is inert due to the stability of its pi electrons being evenly distributed, making it difficult to react. 11. What is the primary reason oxalic acid is easier to decarboxylate than acetic acid? Answer: It has two carboxyl groups and more reactive pi bonds. Oxalic acid's structure allows for easier decarboxylation compared to acetic acid. 12. The reactivity order of alcohols in the Lucas Reaction is 1° < 2° <......................... Answer: 3° This order indicates that tertiary alcohols are more reactive than secondary and primary alcohols. 13. Match the following substances with their respective descriptions: 1. tert- Butyl A. Primary alcohol alcohol 2. Ethyl B. Tertiary alcohol alcohol 3. Isopropyl C. Secondary alcohol alcohol 4. Acetic D. Carboxylic acid acid Answer: Ethyl alcohol = Primary alcohol Isopropyl alcohol = Secondary alcohol tert-Butyl alcohol = Tertiary alcohol Acetic acid = Carboxylic acid 14. Which of the following statements about carboxylic acids is correct? A. Acetic acid has two carboxyl groups. B. Oxalic acid forms a clear solution when decarboxylated. C. Carboxylic acids do not react with bases. D. Oxalic acid decarboxylates easier than acetic acid. Answer: Oxalic acid decarboxylates easier than acetic acid. (D) Oxalic acid is more reactive and easier to decarboxylate compared to acetic acid. 15. Alkanes contain only carbon-carbon double bonds. A. True B. False Answer: False (B) Alkanes are characterized by carbon-carbon single bonds; double bonds are found in alkenes. 16. What type of reaction occurs when hydroxyl (OH) groups in alcohols are displaced? Answer: Lucas Reaction The Lucas Reaction involves the substitution of hydroxyl groups in alcohols with halides. 17. Which of the following statements is true regarding the solubility of alkanes? A. Alkanes only dissolve in polar solvents. B. Alkanes are soluble in water. C. Both kerosene and paraffin are insoluble in water. D. Kerosene and paraffin are soluble in polar solvents. Answer: Both kerosene and paraffin are insoluble in water. (C) Kerosene and paraffin are mixtures of alkanes, which are nonpolar and therefore insoluble in polar solvents like water. 18. Aldehydes can be oxidized while ketones cannot. A. True B. False Answer: True (A) Aldehydes are easily oxidized, whereas ketones are resistant to oxidation. 19. What is the general formula for aldehydes? Answer: RCHO The R group represents any hydrocarbon chain, making the carbonyl group (C=O) terminal in aldehydes. 20. Kerosene and paraffin are unreactive to many reagents due to the strong.................................................. bonds present in saturated alkanes. Answer: sigma The strong sigma bonds in alkanes make them difficult to react with strong acids and bases. 21. Which test results in a silver mirror when applied to formaldehyde? A. Auto-oxidation B. Fehling's Test C. Tollen's Test D. Bisulfate Addition Answer: Tollen's Test (C) Tollen's Test is specific to aldehydes and results in a silver mirror formation with formaldehyde. 22. Match the type of organic compound with their characteristic odors: 1. A. Pleasant odors Ketones 2. B. Pungent odors Aldehydes Answer: Aldehydes = Pungent odors Ketones = Pleasant odors 23. 1,2-dibromoethane is produced through a substitution reaction with ethene and bromine. A. True B. False Answer: False (B) 1,2-dibromoethane is formed through an addition reaction, not a substitution reaction. 24. What is the observation result for Fehling’s Test with formaldehyde? Answer: Brick red precipitate Fehling’s Test gives a brick red precipitate, indicating the presence of an aldehyde.