Principles of Chemistry Flashcards
1
Q
State the three states of matter
A
solids, liquids, gases
2
Q
State the factors on the force of attraction between particles
A
The material
The temp
The pressure
3
Q
Describe the force of attraction in solids
A
strong forces which keep the particles close and fixed
4
Q
Describe the force of attraction in liquids
A
weak force, meaning particles are free to move but tend to stick closely together
5
Q
Describe the force of attraction in gases
A
very weak force, meaning are free to move far apart
6
Q
solid to liquid called?
A
melting
7
Q
liquid to gas called?
A
evaporation
8
Q
describe melting
A
heated (gained energy) solid particles vibrate which weakens the force of attraction to a point til they break free
9
Q
describe evaporation
A
heated (gained energy) liquid particles move faster, weakening the force of attraction until they have enough energy to break free
10
Q
liquid to solid called?
A
freezing
11
Q
gas to liquid called?
A
condensation
12
Q
solid to gas called?
A
subliming
13
Q
Define diffusion
A
gradual movement of particles from high concentration to low concentration
14
Q
What are the three experiments for diffusion?
A
Potassium Manganate (VII) and Water
Ammonia and Hydrogen Chloride
Bromine Gas and Air
15
Q
Describe the Potassium Manganate (VII) and Water Test
A
Potassium Manganate (VII) is purple
Add Potassium Manganate (VII) to a beaker of water
The purple colour spreads out, as the particles are diffusing out among the water particles
16
Q
For the Potassium Manganate (VII) and Water Test, why does the purple colour get evenly spread out?
A
Particles in a liquid move in a random motion
17
Q
Describe the nucleus
A
contains protons and neutrons
positive charge because of protons
18
Q
Describe electrons
A
move around nucleus in shells
negative charge
19
Q
what is the relative mass of a proton?
A
1
20
Q
what is the relative mass of a neutron?
A
1
21
Q
what is the relative mass of an electron?
A
1/2000
22
Q
what is the relative charge of a proton?
A
positive
23
Q
what is the relative charge of a neutron?
A
no charge
24
Q
what is the relative charge of an electron?
A
negative
25
what is the number of electrons the same as ?
number of protons
26
what is the mass number?
protons + neutrons
| bigger number
27
what is the atomic number?
number of protons (electrons)
| smaller number
28
describe what a molecule is
groups of atoms joined together
| held together by covalent bonds
29
what is an element?
One type of atom joined together
30
Describe compounds
two or more different elements chemically bonded
bond in chemical reactions
very difficult to separate the original elements
properties of the compound is different from original elements
31
Describe mixtures
| An example?
no chemical bond involved
can be separated by physical methods like distillation
Air for example is a mixture of gases
32
what are the uses for filtration?
separate insoluble solid from a liquid
| also can be used for purification
33
what is the use for crystallisation ?
separate a soluble solid from a solution
34
what is the process of crystallisation ?
pour solution into evaporating dish
slowly heat solution, stop when crystals start forming
put dish in warm place to evaporate (get big crystals)
dry using a drying oven or desiccator
35
what is a desiccator ?
drying device which contains chemicals that removes water from surroundings
36
what is rock salt ?
mixture of salt and sand
| salt dissolves in water, sand doesn't
37
describe the process of separating rock salt
Grinding - grind rock salt using pestle and mortar
Dissolving - dissolve in beaker and stir
Filtering - filter through filter paper in a funnel
Crystallisation - evaporate in an evaporating dish
38
explain how the separating rock salt process works
sand is insoluble so doesn't fit through filter paper
salt is soluble so dissolves in solution and goes through filter paper
solution then gets evaporated leaving the salt crystals
39
what is the use for simple distillation ?
used for separating out liquid from a solution
40
what is the use for fractional distillation ?
used for separating a mixture of liquids
41
who created the periodic table? when?
Dmitri Mendeleev in 1869
42
what is the name for Group 1 elements ?
alkali metals
43
what is the name for Group 0 elements ?
noble gases
44
what is the name given for Group 7 elements ?
halogens
45
what do elements in the same group have similar ?
similar properties
46
what is electrostatic attraction ?
| what properties does it give?
strong attraction in ionic compounds due to attraction of opposite charges
gives ionic compounds high melting and boiling points
47
what is oxidation ?
loss of electron
| gain of oxygen
48
what is reduction ?
gain of electron
| loss of oxygen
49
state what an ion is
positively / negatively charged atom
50
state what a cation is
positive ion
51
state what an anion is
negative ion
52
what is ionic bonding between ?
a non metal and a metal
53
Describe ionic compounds
| Properties?
electrostatic attraction gives them a high melting and boiling point
2+ and 2- ions have stronger attraction that 1+ and 1-
ions held together in 3D lattice arrangement
have giant ionic structures
conduct electricity when liquid/molten
54
what is covalent bonding ?
atoms sharing electrons for a full outer shell
55
Describe simple covalent substances
| Properties?
atoms in a molecule held strongly with covalent bonds
forces attraction between the molecules are very weak
results in low melting/boiling point as easily parted
most are gas/liquid at room temp
56
Describe giant covalent structures
| Properties ?
similar to giant ionic structures but no charged ions
atoms bonded with very strong covalent bonds
very high melting/boiling point
don't conduct electricity ever (except graphite)
insoluble in water
57
Describe diamond
| what is it made up of? Uses?
giant covalent structure
each carbon atom forms four covalent bonds
hardest natural substance
used in drill tips and cutting tools
58
Describe graphite
Made up of? Uses?
How is it different to others giant covalent structures?
giant covalent structure
each carbon atom forms three covalent bonds
this creates layers which slide over each other
useful as a lubricant
free electrons - only non metal to conduct electricity
59
what is covalent bonding between ?
a non metal and a non metal
60
Mg + HCl -- MgCl + H²
| what are the reactants / products ?
Mg+HCl--MgCl+H²
| reactants--products
61
what does (aq) mean?
aqueous (dissolved in water)
62
what are isotopes ?
different atomic forms of the same element, which have the same number of protons but different numbers of neutrons
63
what is the symbol for relative atomic mass?
Ar
64
what is relative abundance ?
percentage of that particular isotope in nature
65
what is the relative atomic mass?
mass of an atom
| averaged of all isotopes of an element
66
what is the relative formula mass ?
| Symbol?
Mr
| all the relative atomic mass added together in a compound
67
state what empirical formula is
simplest formula that tells you the ratio of different elements in a compound
Fe⁶O¹² goes to FeO²
68
what is molecular formula?
the actual number of atoms each element has in a compound
69
what is the name for mass of product ?
yield
70
what is the theoretical yield ?
calculated mass
71
percentage yield =
actual yield / theoretical yield
72
Avogadro's number is ...
6.023 x 10²³
73
what is molar mass?
mass of 1 mole
74
moles =
mass / FM
75
what is the molar volume for gas ?
One mole of any gas occupies 24 dm³
| at room temp and pressure
76
1dm³ = how many cm³ ?
1000cm³
| its also a litre
77
state room temperature and pressure
25°C and 1 atmosphere
78
what is the volume unit ?
dm³
79
what is the unit for concentration ?
mol/dm³
| can be g/dm³
80
concentration =
moles / volume
81
what is the symbol for sulfuric acid ?
H²SO⁴
82
state what electric current is
flow of electrons or ions
| electrons/ions can act as charge carriers
83
How can ionic compounds conduct electricity while molten/liquid?
ions need to be free for charge to pass through
| when liquid/molten, ions are free and so conduct electricty
84
Why can't covalent compounds conduct electricity?
don't contain ions, so no charge carriers that are free to move as they make bonds by sharing electrons
graphite is an exception (has free electrons)
85
what are metal compounds are held together by ?
metallic bonding
86
Describe metallic bonding
giant structure of positive ions surrounded by a sea of free (delocalised) electrons
this gives metals their properties
87
Why are metals good conductors of electricity and heat?
the free electrons carry electrical current and heat energy through the material
88
why are most metals malleable?
layers of atoms in metals can slide over each other which means they can be hammered or rolled into flat sheets
89
Describe the Ammonia - Hydrogen Chloride test
- Aqueous ammonia gives off ammonia gas
- HCl gives off hydrogen chloride gas
- soak in wool and place on ends of glass tube
- white ring of ammonium chloride forms
90
why does the ammonium chloride ring form closer to HCl?
particles of ammonia are smaller / lighter that hydrogen chloride particles so diffuse air more quickly
91
give an experiment to demonstrate diffusion in gases
fill half a jar with bromine gas, the other with air (separate with glass plate)
remove glass plate and brown bromine gas will slowly diffuse through the air
random motion will mean it will diffuse
92
Halogen displacement reaction colours
Potassium chloride - no reaction
Potassium bromide - orange with chlorine water
Potassium iodide - brown with chlorine / bromine water
93
what is a solute ?
substance dissolved in the solvent
94
what is a solvent ?
substance that dissolves the solute
95
what is a solution ?
mixture after solvent has dissolved the solute
96
what is cobalt chloride paper for ?
testing presence of water (turns blue to pink)
