CHM1 Review for Exam 15

Transcription

1 Topics 1. Organic Compounds a. Hydrocarbons i. Saturated alkanes (all single bonds) ii. Unsaturated alkenes and alkynes b. Functional Groups i. Alcohols ii. Organic Acids iii. Esters iv. Ethers v. Aldehydes vi. Ketones Organic Reactions a. combustion b. addition c. substitution d. esterification e. Polymerization a. Monomer b. Polymer c. Radical polymerization

2 Multiple Choice (2 pts each) 1. Which of the following corresponds to the formula of a saturated hydrocarbon a. H 3 C-CH 3 b. H 2 C=CH 2 c. HC_CH 2. Which of the following is a hydrocarbon? a. C 6 H 14 b. CH 3 OH c. CH 3 CO 2 H 3. Which of the following is the formula of methane? a. CH 4 b. C 2 H 6 c. C 3 H 8 4. Which of the following is a true statement concerning an alkyne? a. The compound contains a carbon-carbon triple bond. b. The compound can not contain carbon-carbon single bond. c. The compound contains a carbon-carbon double bond. 5. What is the correct name for the following compound? H H H H C C C H H H H a. ethane b. propane c. propene 6. What type of compound is shown below a. alcohol b. ether c. organic acid H-O-CH 3

3 7. Which of the following compounds has four carbon atoms in the formula? a. butane b. 2-pentene c. hexane 8. Which of the following does not have a carbon double bonded to an oxygen? a. an organic acid b. an ester c. an ether 9. Organic compounds must contain a. Carbon and hydrogen b. Carbon and oxygen c. Hydrogen and oxygen 10. Which of the following is an alcohol a. ethanoic acid b. ethanol c. ethanal 11. How many hydrogen atoms are in the formula of ethane? a. 2 b. 4 c Which of the following is not an isomer of pentane? a. 2-methylbutane b. dimethylpropane c. 2,3,3-trimethylpentane 13. Which of the following general formulas corresponds to alkanes? a. C n H 2n+2 b. C n H 2n c. C n H 2n-2

4 14. How many pairs of electrons are shared by the carbon atoms in ethyne? a. 1 b. 2 c What is the name of the compound shown below? H O H H H C C C O C H H H H a. methyl ethanoate b. propyl methanoate c. methyl propanoate 16. Which of the following types of organic compounds does not have a nitrogen in the formula? a. aldehydes b. amines c. amides 17. A unsaturated hydrocarbon must have a. all single bonds between the carbon atoms. b. a double bond between the carbon atoms. c. a double or a triple bond between the carbon atoms. 18. How many hydrogen atoms are in 1-butene? a. 4 b. 8 c Which of the following compounds is an incorrect name? a. 1-pentanone b. 2-pentanone c. 3-pentanone

5 20. Anti-freeze contains 1,2 ethanediol, more commonly known as ethylene glycol, which is what type of organic compound? a. aldehyde b. alcohol c. ketone 21. Fragrances and artificial flavors are often what type of organic compound? (1) Esters (2) Monomers (3) Polymers 22. Plastics are what type of organic compounds? (1) Esters (2) Monomers (3) Polymers 23. When gasoline is mixed with air in a closed system and a spark is provided, what type of reaction occurs? (1) Combustion (2) Single replacement (3) Polymerization 24. What is the stoichiometric coefficient of the oxygen in the following unbalanced combustion reaction? CH 3 OH + O 2 CO 2 + H 2 O (1) 1 (3) 3 (2) 2 (4) Which of the following organic reactions is an addition? (1) CH 4 + Cl 2 CH 3 Cl + HCl (2) C 2 H 4 + Cl 2 C 2 H 4 Cl 2 (3) H 3 C-CO 2 H + HOCH 3 H 3 C-CO 2 -CH 3 + H 2 O 26. Many polymers are prepared by a mechanism called radical polymerization. What is a radical? (1) An atom or group of atoms with electrons. (2) An atom or group of atoms with an unpaired electron(s). (3) An electron.

6 27. What is the missing product in the following esterification reaction? (1) H + (2) OH - (3) H 2 O CH 3 -CH 2 -CO 2 H + HO-CH 2 -CH 3 CH 3 -CH 2 -CO 2 CH 2 -CH Which of the following represents the missing reactant in the following substitution reaction? H 3 C-Cl + H 3 C-OH + HCl (1) Cl 2 (3) H 2 O (2) OH - (4) O Which combination of organic acid and alcohol will produce oil of banana, octyl ethanoate? (1) ethanol and octanoic acid (3) ethanal and octanoic acid (2) 1-octanol and ethanoic acid (4) octanal and ethanoic acid 30. What is the name of the ester that can be formed from ethanoic acid and methanol? (1) methyl methanoate (3) ethyl methanoate (2) methyl ethanoate (4) ethyl ethanoate 31. In the following unbalanced addition reaction, what is the stoichiometric coefficient of hydrogen? H-C C-H + H 2 H 3 C-CH 3 (1) 1 (3) 3 (2) 2 (4) Which of the following represents a combustion reaction? (1) CH 3 CH 2 OH + O 2 --> CH 3 COOH + H 2 O (2) C 2 H 4 + Br 2 --> C 2 H 4 Br 2 (3) CH O 2 --> CO H 2 O (4) CH 4 + Br 2 --> CH 3 Br + HBr

7 33. Which of the following polymers can be prepared from chloroethene? (1) Polyethylene (3) Polyacrylamide (2) Polyvinylchloride (4) Polyurethane 34. Which of the following monomers can be used in a polymerization reaction to produce polyvinyl alcohol? (1) ethene (2) ethanol (3) ethenol (4) chloroethene 35. Given the equation: CH 4 + Br 2 --> CH 3 Br + HBr Which type of reaction does this equation represent? (1) addition (2) hydrogenation (3) polymerization (4) substitution 36. Which organic reaction produces rubber and plastics? (1) polymerization (2) esterification (3) saponification (4) fermentation 37. Which type of reaction is represented by the equation below? Note: n and n are very large numbers equal to about (1) esterification (3) saponification (2) fermentation (4) polymerization n C=C (-C C-) n 38. Which formula correctly represents the product of an addition reaction between ethene and chlorine? (1) CH 2 Cl 2 (3) C 2 H 4 Cl 2 (2) CH 3 Cl (4) C 2 H 3 Cl

8 39. Teflon is a saturated polymer having the general formula (-CF 2 -CF 2 -) n, where n is some very large number. Which of the following monomers is used to prepare Teflon? (1) CH 2 F 2 (3) C 2 F 6 (2) CF 4 (4) C 2 F Given the equation: C 2 H 6 + Cl 2 C 2 H 5 Cl + HCl This reaction is best described as (1) addition involving a saturated hydrocarbon (2) addition involving an unsaturated hydrocarbon (3) substitution involving a saturated hydrocarbon (4) substitution involving an unsaturated hydrocarbon Short Answer Car Chemistry: What's the Deal with Octane Ratings? Kevin_McCue Should you occasionally treat your car to high-octane gas? After all, it is more expensive. A gallon of regular (87-octane) gas at my local filling station is now $1.71. Premium gas (92-octane) is $1.92 per gallon. It s premium, it must be more powerful and better for an engine, right? Actually, no the octane rating of gasoline has nothing to do with the power of a fuel or its ability to clean an engine. It is just more expensive to make. What is an octane rating then? To understand the octane rating, you need to know a little about the modern internal combustion engine. In four-stroke engines, one of the strokes is called the compression stroke. During a normal compression, a fuel/air mixture is compressed in a combustion chamber and then ignited by the spark plug. When a fuel ignites under pressure before the spark, an abnormal, premature explosion occurs. This causes a pinging or knocking sound in the engine, lowers power output, and can lead to engine damage over time. The octane rating (or number) of a fuel is a measure of its ability of to resist ignition under pressure.

9 The different grades of gasoline available at the pump are a complex mixture of hydrocarbons and additives meant to boost octane or act as detergents. They are rated based on their ability to resist knocking against a standard mixture of two hydrocarbons, isooctane and heptane. Isooctane is a branched hydrocarbon that is very good at resisting ignition under pressure. Pure isooctane is the basis of a 100 octane rating. Heptane, on the other hand, ignites easily and is assigned 0 octane. Mixtures of the two hydrocarbons supply the numbers in between. Essentially, regular 87-octane gasoline has the same ability to resist combustion under pressure as a mixture of 87% isooctane and 13% heptane. What octane gas should go in my car? Put in exactly the octane recommended for your car s engine. Some high performance engines use higher compression ratios and thus require higher-octane gas, but most cars use just regular 87-octane gas. It must be emphasized that high-octane gas does not provide more power and does not clean your engine better (in fact the EPA mandates that all grades have the same detergent additives). The only time you should consider using a higher-octane gas is if your engine starts to knock or ping. Probably the safest advice is to switch to the next highest octane and get your car in for a tune-up or repair as soon as possible. This article was first published on January 13, 2003

10 41. Should you occasionally treat your car to high-octane gas? 42. What causes a pinging or knocking? 43. What is the chemical formula of isooctane, written in the form of C x H y where x and y are the number of carbons and hydrogens in the formula respectively? 44. What is the chemical formula of heptane (not the structural formula or Lewis structure)? 45. What is the proper name (IUPAC) for isooctane? 46. What are the percentages of isooctane and heptane in a standard gasoline mixture that has an octane rating of 89? 47. Briefly explain what makes isooctane and octane isomers of one another.

11 Drawing Structures of Organic Compounds Draw the Lewis structures of the following organic compounds ,2-dichlorohexane butanol 50. methylcyclohexane butene 52. methyl propanoate

12 Answers 41. a 42. a 43. a 44. a 45. b 46. a 47. a 48. c 49. a 50. b 51. c 52. c 53. a 54. c 55. c 56. a 57. c 58. b 59. a 60. b No, not unless the manufacturer has designed the engine to run on high octane fuel. 42. Improper timing of the ignigtion of the fuel due to compression problems. 43. C 8 H C 7 H ,2,4-trimethylpentane % isooctane and 11% heptane 47. They have the same formulas but different structures.