Organic Chemistry Flashcards
Define organic (old and new definitions)
old - chemicals that come from living organisms
new - compounds based on carbon, with other elements such as H, O, N
Define homologous series
a group of chemicals with the same general formula, a pattern of physical properties and similar chemical properties
Define hydrocarbons
compounds consisting of only C + H atoms
Define alkanes
hydrocarbons with only single bonds
How do you name organic substances?
prefix (additional atoms)
root of word (noº of C atoms)
suffix (homologous series)
What do you call an alkane with 2 C atoms?
ethane
What is the general formula for alkanes?
CₙH₂ₙ ₊ ₂
Fill in the root of the word for each of the number of C atoms:
noº of C atoms
1 -
2-
3 -
4 -
5 -
6 -
7 -
8 -
9 -
10 -
1 - meth
2- eth
3 - prop
4 - but
5 - pent
6 - hex
7 - hept
8 - oct
9 - non
10 - dec
Write the structural formula for butane
CH₃CH₂CH₂CH₃ or CH₃(CH₂)₂CH₃
What are the physical properties of alkanes?
What are the mpt, viscosity, volatility, and color like?
- covalent discrete
mpt
- increases due to more IMFs
viscosity
- increrases due to more IMFs and larger molecules inter-twine
volatility
- decreases due to increasing bpt
color
- colorless → yellow → black
Define viscosity
resistance to liquid flow
Define volatility
ease of turning into a gas
To recap: What are the properties of covalent discretes?
- low mpt
- insulator
- soluble in oils
★ New topic: Isomers ★
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Define isomers
compounds with the same molecular formula but different arrangement of atoms (dif. structural formula)
Define prefix in the context of naming chemicals
any additional atoms not yet included
Trick to remember isomers:
cannot go through carbons in a line without lifting the pen
What are the rules to name isomers?
number where ‘extra’ atoms are - (number of extra Cs)(number of extra Cs in a row)(yl)(number of Cs in a row)(homolugous series)
What is the method for measuring the enthalpy change for metal + acid?
1) measure 10 cm³ of acid into caliometer
2) measure approximately x g (0.50 g) of metal
3) measure the initial temperature of the acid
4) add metal to acid, start timing
5) record temperature every 15 seconds until temp. starts to decrease (3 readings after it starts decreasing)
★ New topic: Reactions of Alkanes ★
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Are alkanes usually reactive or unreactive?
unreactive
Why are alkanes generally unreactive?
because they only contain strong single covalent bonds (saturated)
In what forms can energy be provided to make alkanes react (Ea)?
1) heat
2) electricity
3) light
What are the 3 types of reaction that alkanes undergo?
1) substitution
2) combustion
3) decomposition
Give an example of substitution with ethane and chlorine
ethane + chlorine −U.V. light→ chloroethane + hydrogen-chloride
Alkane + halogen →
haloalkane + hydrogen halide
Methane + bromine →
bromomethane + hydrogenbromide
Multiple prefixes →
arrange alphabetically (ignoring di, tri, tetra, etc.)
Propane + fluorine
either 1- fluoropropane
or 2- fluoropropane
★ New topic: Combustion ★
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What is the equation for complete combustion?
alkane + oxygen → carbon dioxide + water
Pick the correct answer:
butane + oxygen → cardon dioxide + water
or
butane + oxygen → butoxide
butane + oxygen → cardon dioxide + water
OBVI
What are the 2 equations for incomplete combustion?
alkane + oxygen → carbon monoxide + water
alkane + oxygen → carbon (soot) + water
How could you avoid incomplete combustion with carbon monoxide?
ventillation
Why is carbon monoxide toxic?
it replaces oxygen in haemoglobin
Why are the downsides to soot when doing incomplete combustion?
damages lungs and damages machinery
What does carbon look like?
black solid
★ New topic: Decomposition ★
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What are the conditions needed for decomposition of alkanes?
- heat to 300 ºC
- catalyst of Al₂O₃ / SiO₂
What is the equation for decomposition in alkanes?
large alkane → smaller alkane + alkene
Complete the equation:
C₁₆H₃₄ −xxxxxx→
C₁₆H₃₄−heat + Al₂O₃ → C₉H₂₀ + C₇H₁₄
What is heptene used for? Why is it less useful?
- to make plastic
- less useful because it has low flamibility
★ New topic: Alkenes ★
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Define alkene
hydrocarbons with at least one C =C double bond
Which alkene does not exist?
methene
What is the general formula for alkenes?
CₙH₂ₙ
Name the alkene:
C = C − C
|
C
methylprop-1-ene
What are the properties of alkenes? (physical and chemical)
physical → same as alkanes (covalent bonds do not affect mpt - for discrete covalent. alkenes have slightly lower bpt due to smaller molecules)
chemical → alkenes contain a double bond
What is a double bond from an alkene like?
a single bond which is strong and unreactive and another weaker bond which breaks easily
Could one of the bonds in a double bond in alkenes break and leave the other?
yes
★ New topic: Reactions of alkenes ★
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Define saturated
only has single bonds
Are alkenes saturated or unsaturated?
unsaturated
What causes alkenes to be more reactive than alkanes?
alkenes have a double bond
What happens during an addition reaction with halogens in alkenes in terms of bonds?
double bond breaks, one halogen atom joins on either side of where the double bond was
Which reaction do alkenes undergo?
addition
What is the general formula for an addition reaction with halogens in alkenes? (use ethene)
C₂H₄ + X₂ → C₂H₄X₂
Name the chemical:
prop-1-ene + chlorine →
1,2 - dichloropropane