Chemistry Unit 1 Flashcards

New topic each week

?
  • Created by: Sophie
  • Created on: 15-03-14 12:13
What are the relative charges and masses of the sub-atomic particles?
Proton- +1, mass 1, Neutron- 0, mass 1, Electron- -1, mass 1/1840
1 of 85
How many electrons can the first 3 shells hold?
Up to 2, up to 8, up to 18
2 of 85
Define: Atomic Number
number of protons
3 of 85
Define: Mass Number
number of protons + number of neutrons
4 of 85
What is an isotope?
An atom with the same number of protons but varying numbers of neutrons (and thus varying mass number).
5 of 85
What does carbon dating rely on?
The radioactive isotope Carbon-14. The amount present tells us how long it has been able to decay, and thus the age.
6 of 85
What are the steps in Mass Spectroscopy?
Ionisation, acceleration, deflection, detection
7 of 85
What happens during ionisation?
An electron gun knows electrons from atoms/molecules of the sample so they become positively charged.
8 of 85
What does the amount of deflection depend on?
The mass:charge (m/z) ratio.
9 of 85
How are ions detected?
They strike a detector and accept electrons, thus creating a current proportional to the abundance of each ion.
10 of 85
How many orbitals are there in the 's', 'p' and 'd' sub levels?
1,1 and 3 (respectively)
11 of 85
What is spin?
A property of electrons. Electrons in the same orbital must have opposite spins.
12 of 85
What sub levels are in the 4th energy level?
s, p, d and f (holding a total of 32 electrons)
13 of 85
What is ionisation energy (IE)?
The energy required to remove one mole of electrons from one mole of the gaseous atom (kJ/mol)
14 of 85
Summarise the trends in IE across period 2
Increase from Na to Mg, Decrease from Mg to Al, Increase from Al to P, decrease from P to S, increase from S to Ar. General trend of increasing IE.
15 of 85
Summarise the IE trends down a group?
They decrease- first rapidly and then more slowly.
16 of 85
Why does IE decrease down a group?
Shielding by inner electrons, increased atomic radii.
17 of 85
Define atomic mass (Ar)
average mass of one atom of an element compared to 1/12 the mass of a carbon-12 atom
18 of 85
Define molecular mass (Mr)
average mass of one molecule of a compound compared to 1/12 the mass of a carbon-12 atom
19 of 85
What is a mole?
The amount of a substance that contains 6.022 x 10^23 particles
20 of 85
What are the units for all the components of pV=nRT
p-pressure in Pa, V-volume in m^3, n-number of moles, R- temp in K, T-8.31 J/K/mol
21 of 85
What is 0 degrees Celsius in Kelvin?
273K
22 of 85
Define empirical formula.
simplest ratio of atoms present in a compound
23 of 85
Define molecular formula.
actual numbers of atoms of each type present in one molecule of a compound
24 of 85
What is combustion analysis?
Burning a compound in excess oxygen and measuring the amounts of water, carbon dioxide and other oxides produced
25 of 85
What is the unit of concentration?
mol/dm^3
26 of 85
Define atom economy.
%AE is give as the mass of desired product/total mass of reactants x100
27 of 85
Why is hight atom economy good?
Creates sustainable development, lowers harmful gas emissions
28 of 85
Define % yield.
mass of product obtained/maximum theoretical mass of product x100
29 of 85
When may a low % yield occur?
If the reaction is reversible, product is lost when separated from reaction mixture and if the reactants react in other reactions.
30 of 85
What are the 3 types of strong chemical bond?
Ionic, covalent and metallic
31 of 85
How is ionic bonding defined?
The result of electrostatic attraction between oppositely charged ions.
32 of 85
Give some physical properties of ionic compounds.
High melting point. Conduct electricity as liquids or in solution.
33 of 85
What is the name given to a group of covalently bonded molecules?
molecule
34 of 85
What is co-ordinate bonding?
Dative covalent bonding- both of a pair of electrons come from the same atom.
35 of 85
Define electronegativity.
The ability of an atom to attract the electron density in a covalent bond towards itself
36 of 85
What are the 3 factors that affect e-negativity
Nuclear charge, atomic radius, shielding by electrons
37 of 85
What are the trends of e-negativity throughout groups and periods?
Increases up groups (smaller atomic radius) and across periods (larger nuclear charge).
38 of 85
What are the 3 most e-negative elements?
Fluorine, oxygen then nitrogen
39 of 85
What is polarity?
A property of bonds between atoms with different e-negativities. Atoms have partial charges. (Polar covalent bonds have some ionic character.)
40 of 85
What does the strength of metallic bonding depend on?
The charge on the ion (larger=stronger) and the size of the ion (smaller=stronger)
41 of 85
Give a physical property of metals and explain in terms of bonding why they have this property
Malleable and ductile. Layers of ions can slide over each other but remain in the same environment (charges around them remain the same)
42 of 85
What are the 3 types of intermolecular forces in order from strongest to weakest?
Hydrogen bonds, permanent dipole-dipole interactions, Van de Waals forces
43 of 85
When can molecules have permanent dipole-dipole interactions?
When they have a dipole moment, except when the molecule is symmetrical
44 of 85
When can hydrogen bonds form?
When an F, O or N atom with a lone pair of electrons is present at the same time as a hy
45 of 85
What factor affects the strength of VdW forces?
The surface area of the molecule (larger=stronger)
46 of 85
How many C-C bonds does each C atom form in a) Diamond and b) Graphite?
a) 4 and b) 3
47 of 85
What is the bond angle in a) Diamond and b) Graphite?
a) 109.5 degrees and b) 120 degrees
48 of 85
Give some physical properties of diamond
Very hard, very high melting point, does not conduct electricity.
49 of 85
Why can graphite conduct electricity?
Each C atom has a spare electron in the P orbital. The P orbitals merge above and below the plane of C atoms, creating a sea of electrons which can carry current.
50 of 85
What is the shape and bond angle of water?
V-shaped, 104.5 degrees
51 of 85
What is the shape and bond angle of AlCl(3)?
Trigonal planar, 120 degrees
52 of 85
What is the shape and bond angle of PCl(5)?
Bipyrimidal, 120 and 90 degrees depending on plane
53 of 85
What are the trends in reactivity down the groups of the periodic table?
Reactivity increases down groups in the s-block but up groups in the p-block.
54 of 85
What type of ions do lanthanides form?
3+
55 of 85
Where are elements with giant structures found, and what physical property do they have?
Found on the left of the table, and have high melting points (also conduct electricity)
56 of 85
What does the melting point of elements found on the right of the table tend to be?
Low
57 of 85
Does the strength of metallic bonding increase or decrease across periods?
Increase
58 of 85
Which of sulphur, phosphorus and chlorine has the highest melting point and why?
Sulfur, as it forms S(8) so has the most electrons and thus strongest Van der Waals forces.
59 of 85
How does atomic radius change across periods?
It decreases across periods due to increased nuclear charge.
60 of 85
Define first ionisation energy
The energy required to remove one mole of electrons from one mole of the gaseous element.
61 of 85
How does first ionisation energy change across period 3?
General increase with decreases between Mg and Al, and P and S.
62 of 85
What is the electronic structure of copper?
1s2,2s2,2p6,3s2,3p6,3d10,4s1
63 of 85
What is the difference between structural and displayed formulae?
Displayed formula shows all the bonds, structural only shows arrangement.
64 of 85
What is a functional group?
The group of atoms that give a family of organic compounds their characteristic properties.
65 of 85
Define: Homologous series
A group of organic compounds with the same functional group and general formula. Members show trends in physical properties.
66 of 85
What is the functional group of carboxylic acids?
-COOH
67 of 85
What is the functional group of aldehydes?
-C(=O)(-H)
68 of 85
What takes priority when naming organic compounds?
the functional group
69 of 85
What determines the written order of R groups?
they are written alphabetically
70 of 85
Give the 3 types of structural isomerism.
Chain, positional, functional group
71 of 85
Define: chain isomers.
Have the same molecular formula but different lengths of carbon chain.
72 of 85
Define: functional group isomers.
Have the same molecular formula but different functional groups. Aldehydes and ketones can be functional group isomers, as can alkenes and cycloalkanes.
73 of 85
Give 3 physical or chemical properties of alkanes.
Physical: Boiling points increase as chain length increases, insoluble in water, do not conduct electricity. Chemical: unreactive with acids, bases, oxidising/reducing agents, will burn in oxygen, non polar, will react with halogens.
74 of 85
Where do short-chain hydrocarbons form in a fractionating tower.
Near the top.
75 of 85
What is formed near the base of a fractionating tower?
Tar/bitumen
76 of 85
Where is crude oil heated during fractional distillation?
In a furnace.
77 of 85
What are the two types of cracking?
Thermal and catalytic.
78 of 85
Why do we want to produce shorter-chain hydrocarbons?
They are more valuable.
79 of 85
Give two differences between catalytic and thermal cracking?
Catalytic uses lower temp, lower pressure, zeolite catalyst and forms alkanes cycloalkanes and aromatic compounds. Thermal: initially produces free-radicals and forms both alkanes and alkenes.
80 of 85
What can be used to remove sulphur from fuels and why is this done?
CaO or CaCo(3) can be used. Removing sulphur means SO(2) cannot be formed which causes acid rain.
81 of 85
What can the alkenes produced in thermal cracking be used for?
To make polymers (plastics).
82 of 85
Describe the structure of a catalytic converter.
Honeycomb structure to give large surface area, made of ceramic metal.
83 of 85
What are the metal catalysts in a catalytic converter?
Platinum and rhodium.
84 of 85
What does a catalytic converter remove from exhaust fumes?
CO and NO
85 of 85

Other cards in this set

Card 2

Front

How many electrons can the first 3 shells hold?

Back

Up to 2, up to 8, up to 18

Card 3

Front

Define: Atomic Number

Back

Preview of the front of card 3

Card 4

Front

Define: Mass Number

Back

Preview of the front of card 4

Card 5

Front

What is an isotope?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Foundation Chemistry resources »