Brainscape's Knowledge GenomeTM


Top Flashcards (Certified)
All Flashcards

Chemistry > DF definitions and concepts > Flashcards

DF definitions and concepts Flashcards

1
Q

enthalpy change

A

heat energy change measured under a constant pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

ideal gas

A

model of gases that assumes that gas molecules are perfect spheres that move in straight lines at a constant speed

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

displayed formula

A

shows the relative positions of atoms and all the bonds between them

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

empirical formula

A

simplest whole number ratio of atoms of each element present in a compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

skeletal formula

A

simplified organic formula shown by removing hydrogen atoms from alkyl chains, leaving the carbon skeleton and the functional groups

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

structural formula

A

shows arrangement of atoms in a molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

sigma bond

A
  • type of covalent bond which forms when atomic orbitals overlap head on
  • they can rotate freely
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

pi bond

A
  • type of covalent bond formed when adjacent p orbitals overlap sideways above and below the bonding C atoms
  • pi bonds cannot rotate
  • have a low bond enthalpy so alkenes are more reactive than alkanes
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

average bond enthalpy

A

enthalpy change when one mole of a specified covalent bond is broken, averaged out across the range of compounds

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

endothermic

A
  • reaction that takes in energy from surroundings
  • bonds breaking
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

enthalpy

A

value that represents the heat content of a system

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

enthalpy change

A

heat energy change measured under a constant pressure

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

enthalpy change of neutralisation

A

enthalpy change that takes place when one mole of water is formed from a neutralisation reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

enthalpy change of reaction

A

enthalpy change that is associated with a particular chemical reaction

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

exothermic

A
  • reaction that releases energy into surroundings
  • bonds making
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

hess’s law

A

enthalpy change of a reaction is independent of the route taken

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

standard conditions

A

solution concentrations of 1.00 mol dm-3, pressure 100kPa and temperature is generally 298K

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

standard state

A

physical state of a substance under standard conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

standard enthalpy of combustion

A

enthalpy change when one mole of a substance is burned completely in excess oxygen under standard conditions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

standard enthalpy of formation

A

enthalpy change when one mole of a substance in its standard state under standard conditions is formed from its elements

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

activation energy

A

minimum amount of energy for particles to collide with for a successful reaction to take place

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

catalysis

A

increase in rate of a reaction by the use of a catalyst

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

catalyst

A

substance that speeds the rate of reaction without being used up by lowering the activation energy and provides an alternate pathway

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

catalyst poisoning

A

decrease in the activity of a heterogeneous catalyst due to another compound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
cracking
process of breaking long chain alkanes into smaller more useful hydrocarbons
26
heterogeneous catalyst
catalyst that is in a different state as the reactants
27
hydrocarbon
compound that contains hydrogen and carbon atoms only
28
aliphatic compound
organic compound that is made up of straight or branched chains
29
alkane
homologous series of saturated hydrocarbons with the general formula CnH2n+2
30
alkene
hydrocarbon containing at least one C=C double bond with the general formula CnH2n
31
global warming
increase in the global temperature due to an increase in greenhouse gasses and other pollutants being released into the atmosphere
32
homologous series
series of compounds with the same functional group and similar chemical properties
33
nomenclature
naming of a molecule/compound in chemistry
34
organic compound
carbon containing compound
35
pollutant
substance that has an undesired effect on the air, water or environment
36
saturated
organic compound which only contains C-C single bonds
37
structural isomers
compounds with the same molecular formula but different structural formulae
38
unsaturated
organic compound that contains at least one double bond C=C, a triple bond or an aromatic ring
39
addition polymer
- formed by addition polymerisation - formed from monomers with C=C bonds
40
addition polymerisation
- process by which addition polymers are formed - lots of short chain monomers (alkenes) join to form a long chain polymer by the opening of double carbon bonds
41
monomer
small molecule used to form polymers
42
polymer
large molecule made from monomers bonded together
43
polymerisation
- process of making a polymer from its monomers - two types: addition polymerisation and condensation polymerisation
44
repeat unit
- structure within a polymer that appears over and over again
45
addition reaction
where molecules combine to form a single product
46
carbocation
compound containing a carbon atom bearing a positive charge
47
curly arrow
shows movement of a pair of electrons
48
electrophile
electron pair acceptor
49
electrophilic addition
reaction in which a pi bond us broken and two new sigma bonds form as a result of the addition of an electron pair acceptor (electrophile)
50
major/minor products
- formed in electrophilic addition reactions due to the differing relative stabilities of the primary/secondary/tertiary carbocation intermediates - major product is formed from the most stable intermediate - minor product is formed from the least stable intermediate
51
primary carbocation
- molecule in which the carbon with the positive charge is only attached to one alkyl group - least stable carbocation
52
secondary carbocation
- positive carbon is attached to two alkyl groups - more stable than primary but less stable than tertiary
53
tertiary carbocation
- positive carbon is attached to three alkyl groups - most stable
54
cis-trans isomerism
- cis have same side of double bond - trans have opposite sides of double bond
55
E/Z isomerism
- Z is on same side of double bond - E is on opposite side of double bond
56
stereoisomers
compounds with the same structural formula but a different arrangement of atoms in space
57
structural isomers
compounds with the same molecular formula but different structural formulae
58
biofuels
- fuels made from once-living organic matter - renewable and sustainable - alternative to fossil fuels
59
complete combustion
- when a compound is burnt in an excess of oxygen - when alkanes are completely combusted the only products are water and CO2
60
hydrogen fuel cell
- electrochemical cell that converts the chemical energy of hydrogen and oxygen which is an oxidising agent into electricity through redox reactions - don't need to be recharged but require a constant supply of fuel to maintain the potential difference
61
incomplete combustion
- when a compound is burnt in a limited supply of oxygen - when alkanes are incompletely combusted, water, carbon monoxide, carbon particulates and some CO2 may be produced

Chemistry (8 decks)

Brainscape helps you reach your goals faster, through stronger study habits.
© 2025 Bold Learning Solutions. Terms and Conditions