Chapter 10 Organic Answers

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Name______________________________________________period______IB chemistry ch. 10 organic chemistry
1. What makes carbon able to form so many different compounds? It bonds to itself to form long chains
2. What is the maximum number of other atoms to which a given carbon atom can be attached? Why? Four; this will give it 8
electrons in its highest shell
3. What does a double bond represent? Give two examples of molecules in which double bonds occur, and draw the Lewis
structures of those molecules. Four electrons being shared; CO2 O=C=O and C2H4
4. For each of the following straight-chain alkanes draw the structural formula and give the condensed structural formula
a. heptane
b. nonane
c. propane
CH3-CH2-CH2-CH2-CH2-CH2-CH3
CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
CH3-CH2-CH3
C7H16
C9H20
C3H8
d. decane CH3-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH2-CH3
C10H22
5. Molecules with the same chemical formulas but different organization of atoms; butane
6. What is a small chain of carbon atoms called when it is attached to a longer chain of carbon atoms? substituents
7. To what does the root name for a branched hydrocarbon correspond? Number of carbon atoms in the longest chain
8. How is the position of substituents along the longest chain of a hydrocarbon indicated? Number of the lowest carbon that it is on
is placed before the name
9. In giving the name of a hydrocarbon with several substituents, in what order do we list the substituents?alphabetical
10. Which of the following formulas represent alkanes?
a. CH2
b. C2H6
d. C7H16
e. C9H20
11. Write the molecular formula of an alkane that contains
c. C5H10
f. C13H26
a) 12 C atoms C12H26
(b)50 H atoms C24H50
12. Draw the full structural formula for 3-ethyl-2,6,6-trimethylheptane
CH3
CH3
CH3-CH-CH-CH2-CH2-C-CH3
CH2CH3
CH3
13. Give the IUPAC name for each of the following alkanes.
a. 3,3-diethyl-4-methylhexane
b. 3-ethyl-5-propyloctane
14. Draw all of the possible non-cyclic structural isomers of C5H12. Name each compound.
pentane, 2-methylbutane,
2,2-dimethylpropane
15. Using condensed structural formulas, write the balanced equation for the addition reaction of 2,3-dimethyl-2-butene with Br2
CH3C(CH3)=C(CH3)CH3 + Br2  CH3C(CH3)BrC(CH3)BrCH3
16. Using condensed structural formulas, write the balanced equation for the addition of H 2O to 2-pentene using H2SO4 as a catalyst
(two products).
CH3CHCHCH2CH3 + H2O  CH3CHOHCH2CH2CH3 (major) + CH3CH2CHOHCH2CH3 (minor)
17. Identify the functional groups in each of the following compounds: a. carboxylic acid b. ester c. alcohol d. halogenoalkane
18. Draw the structural formulas for the following aldehydes or ketones:
a. Propanal
b. 2-pentanone
CH3-CH2-CH2-OH
CH3CH2CH2COCH3
c.
3-methyl-2-butanone
d. 2-methylbutanal
CH3CH(CH3)COCH3
CH3CH2CH(CH3)CHO
19. Reaction Pathways: Give reactants and conditions, if necessary, that could be used to make the following
a. 1-butanol reactants: butene
conditions: heat with steam and a catalyst of concentrated sulfuric acid
b.
butanoic acid
c.
Ethanoic acid from ethene (2 steps)
d.
1-butanol from butane (2 steps)
e.
3 hexanone from 3-bromohexane (2-steps)
f.
propanal from 1-bromopropane
All of the following questions are from prior IB Exams
20. The plastic PVC, poly(chloroethene), is made from the monomer chloroethene, C2H3Cl, by a polymerization reaction.
a. Draw the structural formula of chloroethene.
C=C
b. State the type of polymerization reaction that occurs to make poly(chloroethene) and identify the structural feature needed in
the monomer. Double bond
c. Draw the structure of the repeating unit of poly(chloroethene).
d. Explain why monomers are often gases or volatile liquids, whereas polymers are solids. Stronger van der waal forces
21. The alkanes are a homologous series of saturated hydrocarbons.
a. State the meaning of each of the following terms.
i. homologous series a series of compounds with a similar general formula usually varying by a single parameter
ii. hydrocarbon a compound containing only hydrogen and carbon
iii. saturated has the maximum number of hydrogen atoms possible
b. i. State and explain the trend in the boiling points of the first five alkanes.
The boiling points increase due the stronger van der waal forces (bigger molecules have stronger van der waal forces)
ii. Explain why the enthalpies of combustion of alkanes are negative values.
Combustion reactions are exothermic and release energy
c. State the products of the complete combustion of alkanes.
Carbon dioxide and water
22. a. Draw the structural formula of pent-2-ene
CH3-CH=CH-CH2-CH3
b. Write a balanced chemical equation for the complete combustion of pent-2-ene. 2C5H10 + 15O2  10CO2 + 10H2O
c. What is produced during the reaction, other than the chemical products? heat
d. If the supply of oxygen was reduced, what other chemical product might result from the combustion? Carbon monoxide
e. Give one reason why the production of this substance is undesirable. Carbon monoxide makes a person feel dizzy, headache
and irritable due to lack of oxygen in the blood
f. Draw a structural isomer, other than pent-1-ene, and name the compound. 2-methylbut-1-ene or 3-methybut-1-ene or
2 methylbut-2-ene
23. Find the structural formula for cholesterol in the IB data booklet. Both ethanol and cholesterol contain one-OH group. Explain
why ethanol is soluble in water, whereas cholesterol is insoluble in water.
24. C2H4 can be converted into one of the compounds below in a single step reaction.
C2H3Cl
C2H4Cl2
a. Draw the structural formula for each of these compounds and identify the compound that can be formed directly from C 2H4.
b. C2H4 can also react to form a polymer. Name this type of polymer and draw the structural formula of a section of this polymer
consisting of three repeating units.
25. Which compound has the lowest boiling point?
a. CH3CH2CH(CH3)CH3
b. (CH3)4C
c. CH3CH2CH2CH2CH3
d. CH3CH2OCH2CH3
26. What type of reaction does the equation below represent?
CH2=CH2 + Br2  BrCH2CH2Br
a. substitution
b. condensation
c. reduction
d. addition
27. Which statement about neighboring members of all homologous series is correct?
a. They have the same empirical formula
b. They differ by a CH2 group
c. They possess different functional groups
d. They differ in their degree of saturation
28. Which compound is a member of the same homologous series as 1-chloropropane?
a. 1-chloropropene
b. 1-chlorobutane
c. 1 bromopropane
d. 1,1-dichloropropane
29. Which type of compound must contain a minimum of three carbon atoms?
a. an aldehyde
b. a carboxylic acid
c. an ester
d. a ketone
30. What is the IUPAC name for CH3CH2CH(CH3)2?
a. 1,1-dimethylpropane
b. 2-methylbutane
c. isopentane
d. ethyldimethylmethane
31. How many structural isomers are possible with the molecular formula C 6H14?
a. 4
b. 5
c. 6
d. 7
32. Which compound is a member of the aldehyde homologous series?
a. CH3COCH3
b. CH3CH2CH2OH
c. CH3CH2COOH
d. CH3CH2CHO
33. Which formulas represent butane or its isomer?
I CH3(CH2)2CH3?
II CH3CH(CH3)CH3
a. I and II only
b. I and III only
III (CH3)3CH
c. II and III only
d. I, II and IIII
34. Which substance(s) could be formed during the incomplete combustion of a hydrocarbon?
I carbon
a. I only
II hydrogen
b. I and II only
c. I and III only
III carbon monoxide
d. II and III only
35. What is the final product formed when CH3CH2OH is refluxed with acidified potassium dichromate (IV)?
a. CH3CHO
b. CH2=CH2
c. CH3COOH
d. HCOOCH3
Review problems:
36. PH3
CH4
CH2O
SO2
Which of the following molecular shapes is NOT represented among the molecules given above?
a) linear
b) bent
c) trigonal planar
d) trigonal pyramid
e) tetrahedral
37. What volume of 0.500 mol dm −3 sulfuric acid solution is required to react completely with 10.0 g of calcium
carbonate according to the equation below?
CaCO3(s) + H 2SO4 (aq) → CaSO4 (aq) + H2O (l) + CO2 (g)
A. 100 cm3
B.200 cm3
C. 300 cm3
D. 400 cm3
38. Analytical chemists can detect amounts of amino acids as small as 2.0 ×10-21 mol. How many molecules does this
represent?
A. 2.0 x 10 -21
B. 1.2×103
C. 6.0×1023
D. 3.0×1044
39. One stage in the manufacture of nitric acid is the oxidation of ammonia:
__NH3 (g) + __O2 (g) → __NO (g) + __H2O (l)
When the equation is balanced using the smallest possible whole numbers, what is the coefficient for NH3?
A. 2
B.4
C.5
D.6
40. Which substance has the lowest electrical conductivity?
A. Al (s)
B.Al2O3 (l)
C. KCl (aq)
D. HCl (g)
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