• Created by: bbyjujux
  • Created on: 19-04-17 00:11
what does an compound contain?
A compound contains two or more elements which are chemically combined
1 of 131
what is covalent bonding
covalent bonding is sharing electrons - non-metals only
2 of 131
what is ionic bonding
Ionic bonding is – transferring electrons - metal and non-metal
3 of 131
what is chemical bonding
Chemical bonding: involves either transferring or sharing electrons in the highest occupied energy level (outer shell) of atoms to achieve the electronic structure of a noble gas (full outer shell)
4 of 131
what do metals consist of?
Metals consist of giant structures of atoms arranged in a regular pattern.
5 of 131
what are The electrons in the highest occupied energy levels ( outer shell)of metal atoms free to do?
they are delocalised and so they are free to move through the whole structure
6 of 131
what does this create?
This creates a structure of positive ions with electrons between the ions holding them together by strong electrostatic attractions.
7 of 131
polymers and nano materials-are there different types of polymers?
there are different types of polymers with different uses
8 of 131
What do nano-materials have?
Nanomaterials have new properties because of their very small size.
9 of 131
compounds are substances in which.......
atoms of two or more elements are chemically combined.
10 of 131
what does chemical bonding involve?
Chemical bonding involves either transferring (IONIC BONDING) or sharing electrons (COVALENT BONDING)
11 of 131
in the highest occupied energy levels (shells) of atoms in order to ...
achieve the electronic structure of a noble gas.
12 of 131
atoms do what?
13 of 131
what do atoms form chemical bonds by transferring electrons
they form ions.
14 of 131
what happens to atoms when they lose electrons
they become positively charged
15 of 131
what are in group 1 of the periodic table?
the alkali metals
16 of 131
alkali metals react with....
non-metal elements to form ionic compounds in which the metal ion has a single positive charge.
17 of 131
what does alkali metals react with to form ionic compounds
non metal elments
18 of 131
what are the elements in group 7 of the periodic table called
the halogens
19 of 131
what do halogens react with to form ionic compounds
alkali metals
20 of 131
the halogens react with the alkali metals to form....
ionic compounds in which the halide ions have a single negative charge.
21 of 131
what is an ionic compound?
its a giant structure of ions
22 of 131
what are ionic compounds held together by?
Ionic compounds are held together by strong ‘electrostatic forces of attraction’ between oppositely charged ions
23 of 131
in what direction do these forces act?
These forces act in all directions in the lattice and this is called IONIC BONDING.
24 of 131
what do Some covalently bonded substances consist of?
simple molecules such as H2, Cl2, O2, HCl, H2O, NH3 and CH4.
25 of 131
what are other giant covalent structures
(macromolecules), such as diamond and silicon dioxide.
26 of 131
what do simple molecules consist of
they consist of gases, liquids or solids that have relatively low melting points and boiling points
27 of 131
do simple molecules conduct electricity
no they do not conduct electricity because the molecules do not have an overall electric charge
28 of 131
what is intermolecular forces
Substances that consist of simple molecules have only weak forces between the molecules areintermolecular forces called
29 of 131
why do ionic bonds have high boiling points
because of the large amounts of energy needed to break the many strong bonds.
30 of 131
what can ionic bonds do when melted or dissolved in water
When melted or dissolved in water, ionic compounds conduct electricity because the ions are free to move and carry the current.
31 of 131
atoms that share electrons can form what?
form giant structures or macromolecules.
32 of 131
what are diamond and graphite an example of?
of giant covalent structures (lattices) of atoms.
33 of 131
All the atoms in these structures......
are linked to other atoms by strong covalent bonds and so they have very high melting points..
34 of 131
what is in graphite
In graphite, each carbon atom bonds to three others, forming layers. The layers are free to slide over each other because there are no covalent bonds between the layers and so graphite is soft and slippery.
35 of 131
why does graphite have these properties
Graphite has these properties because of the weak intermolecular forces between the layers.
36 of 131
why is diamond really hard
In diamond, each carbon atom forms four covalent bonds with other carbon atoms in a giant covalent structure, so diamond is very hard.
37 of 131
what is one electron in each carbon atom in graphite
its delocolised
38 of 131
what does this allow the electrons to do
These delocalised electrons allow graphite to conduct heat and electricity.
39 of 131
what is graphite similar to?
graphite is similar to metals in that it has delocalised electrons.
40 of 131
what can carbon also form?
fullerness with different numbers of carbon atoms
41 of 131
what can fullerness be used for?
drug delivery into the body, in lubricants, as catalysts, and in nanotubes for reinforcing materials, e.g. in tennis rackets.
42 of 131
what is the structure of fullerneses based on
hexagonal rings of carbon atoms
43 of 131
what can metals conduct?
heat and electricity
44 of 131
why can they conduct heat and electricity?
because of the delocalized electrons in their structures
45 of 131
what are the layers of atoms in metalsable to do
they are able to slide over each other and so metals can be bent and shaped.
46 of 131
what are alloys made of?
Alloys are usually made from two or more different metals.
47 of 131
what is difficult for alloys to do and why?
it is difficult for alloys to slide of each other because the different sized atoms of the metals distort the layers in the structure
48 of 131
so what makes alloys harder than
pure metals
49 of 131
what can shape memory alloys do?
Shape memory alloys can return to their original shape after being deformed
50 of 131
what does the properties of polymers depend on?
The properties of polymers depend on what they are made from and the conditions under which they are made.
51 of 131
what do thermosoftening polymers consist of
Thermosoftening polymers consist of individual, tangled polymer chains.
52 of 131
what do thermosetting polymers consist of
Thermosetting polymers consist of polymer chains with cross-links between them so that they do not melt when they are heated
53 of 131
what does thermosofeting polymers have
Thermosoftening polymers in terms of have weak intermolecular forces of attraction between the polymer chains so are soft and can me melted easily
54 of 131
nanosciene- what does nanoscience refer to?
Nanoscience refers to structures that are 1–100nm in size, of the order of a few hundred atoms. (VERY SMALL)
55 of 131
what do nanoparticels show
Nanoparticles show different properties to the same materials in bulk and have a high surface area to volume ratio
56 of 131
what does this may lead to the development of
new computers, new catalysts, new coatings, highly selective sensors, stronger and lighter construction materials, and new cosmetics such as sun tan creams and deodorants.
57 of 131
what is The relative formula mass (Mr) of a compound
its the sum of the relative atomic masses of the atoms in the numbers shown in the formula.  
58 of 131
what is The relative formula mass of a substance, in grams, known as
its is known as one mole of that substance
59 of 131
analyzing substances- how can elements and compounds be detected?
Elements and compounds can be detected and identified using Instrumental methods.
60 of 131
what are instrumental methods
Instrumental methods are accurate, sensitive and rapid and are particularly useful when the amount of a sample is very small.
61 of 131
what can Chemical analysis can be used for
it can be used to identify additives in foods.
62 of 131
what can artificial colors be detected and identified by
paper chromatography
63 of 131
what is Gas chromatography linked to mass spectroscopy (GC-MS an example of
an instrumental method
64 of 131
what does Gas chromatography allow?
its allows the separation of a mixture of compounds
65 of 131
The time taken for a substance to travel through the column can be used to...
help identify the substance
66 of 131
what can The output from the gas chromatography column link to?
it can be linked to a mass spectrometer, which can be used to identify the substances leaving the end of the column
67 of 131
what can The mass spectrometer can also give?
the relative molecular mass of each of the substances separated in the column.
68 of 131
how does gc-ms work
different substances, carried by a gas, travel through a column packed with a solid material at different speeds, so that they become separated
69 of 131
what does ■ the number of peaks on the output of a gas chromatograph show?
it shows the number of compounds present
70 of 131
what is the moclecular mas given by?
The molecular mass is given by the molecular ion peak.
71 of 131
what does the position of the peaks on the output indicate?
the position of the peaks on the output indicates the retention time
72 of 131
what can a mass spectrometer dentify
a mass spectrometer can identify substances very quickly and accurately and can detect very small quantities.
73 of 131
how can the percentage of an element in a compound be calculated?
it can be calculated from the relative mass of the element in the formula and the relative formula mass of the compound.
74 of 131
how can the empirical formula of a compound can be calculated
it can be calculated from the masses or percentages of the elements in a compound.
75 of 131
how can the The masses of reactants and products be calculated
from balanced symbol equations.
76 of 131
what is the yield knows as
The amount of a product obtained
77 of 131
what is a percentage yield
When compared with the maximum theoretical amount as a percentage, it is called the percentage yield.
78 of 131
why is the % yield never 100%
Even though no atoms are gained or lost in a chemical reaction, it is not always possible to obtain the calculated amount of a product
79 of 131
the reaction may not go to completion because it is reversible ■ some of the product may be lost when it is separated from the reaction mixture ■ some of the reactants may react in ways different from the expected reaction.
80 of 131
what can some chemical reactions, the products of the reaction can react to produce
the original reactants. such reaction are called reversible reactions and are represented as A+B C+D
81 of 131
rates of reaction- what can the rate of a chemical reaction be found by?
can be found by measuring the amount of a reactant used or the amount of product formed over time:
82 of 131
what are the 2 definitions of the rate of reaction
Rate of reaction = amount of reactant used time Rate of reaction = amount of product formed time
83 of 131
when can Chemical reactions only occur
it can only occur when reacting particles collide with each other and with sufficient energy.
84 of 131
what is an activation energy
The minimum amount of energy particles must have to react is called the activation energy.
85 of 131
what can does the temperature do to the rate of reaction to particles
it increases the speed of the reacting particles so that they collide more frequently and more energetically. This increases the rate of reaction.
86 of 131
what does increasing the pressure do to the rate of the reaction of gases?
Increasing the pressure of reacting gases increases the frequency of collisions and so increases the rate of reaction.
87 of 131
what does increasing the rate of concretion do to reactants in solutions?
it increases the frequency of collisions and so increases the rate of reaction
88 of 131
what does Increasing the surface area do to solid reactants
it increases the frequency of collisions and so increases the rate of reaction
89 of 131
what are catalysts not used up for?
catalyts are not used up during the reaction.Different reactions need different catalysts.
90 of 131
what are catalyts important for?
Catalysts are important in increasing the rates of chemical reactions used in industrial processes to reduce costs.
91 of 131
what happens when chemical reactions occur
energy is transferred to or from the surroundings.
92 of 131
what does exothermic do
An exothermic reaction is one that transfers energy to the surroundings. (temp increases)
93 of 131
what are examples of exothermic reactions include combustion,
, many oxidation reactions and neutralisation.
94 of 131
exothermic reaction is an...
Everyday uses of exothermic reactions include self-heating cans (eg for coffee) and hand warmers
95 of 131
what is an edothermic reaction?
An endothermic reaction is one that takes in energy from the surroundings. (temp decreases
96 of 131
what does Endothermic reactions include?
thermal decompositions
97 of 131
what are some sport injury packs based upon?
endothermic reactions.
98 of 131
what happens if a reversible reaction is exothermic is in one direction,
it is endothermic in the opposite direction. The same amount of energy is transferred in each case.
99 of 131
Making salts- what are the state symbols in equation
The state symbols in equations are (s = solid), (l= liquid), (g) and (aq = aqueous).
100 of 131
Soluble salts can be made by reacting acids with...
metals – not all metals are suitable; some are too reactive and others are not reactive enough insoluble bases – the base is added to the acid until no more will react and the excess solid is filtered off alkalis – an indicator can be used to show
101 of 131
how can insoluble salts be made?
These can be made by mixing appropriate solutions of ions so that a precipitate is formed.
102 of 131
what can precipitation be used for
Precipitation can be used to remove unwanted ions from solutions, for example in treating water for drinking or in treating effluent
103 of 131
what does the the particular salt producein any reaction between an acid and a base or alkali depend on
the acid used (2nd word of the name) (hydrochloric acid produces chlorides, nitric acid produces nitrates, sulphuric acid produces sulfates) ■ the metal in the base or alkali (1st word in the name)
104 of 131
what are Metal oxides and hydroxides
105 of 131
what are soluble hydroxides called
106 of 131
what does ammonia dissolve in
Ammonia dissolves in water
107 of 131
to produce what
to produce an alkaline solution. It is used to produce ammonium salts.
108 of 131
what are Ammonium salts
important as fertilisers
109 of 131
what does Hydrogen ions, H+(aq), make
solutions acidic
110 of 131
what does hydroxide ions, OH–(aq), make
solutions alkaline
111 of 131
what is a ph scale
The pH scale is a measure of the acidity or alkalinity of a solution
112 of 131
what does hydrogen react with in neutralisation reactions
hydrogen ions react with hydroxide ions to produce water. This reaction can be represented by the equation: H+(aq) + OH–(aq) ➞ H2O(l)
113 of 131
electrolysis- what happens When an ionic substance is melted or dissolve in water
the ions are free to move about within the liquid or solution.
114 of 131
what happens if you pass an electric current through ionic substances that are molten for example lead bromide or in solution
breaks them down into elements. This process is called electrolysis and the substance that is broken down is called the electrolyte.
115 of 131
what happens during electrolysis
During electrolysis, positively charged ions move to the negative electrode, and negatively charged ions move to the positive electrode.
116 of 131
what is electrolysis used to do
Electrolysis is used to electroplate objects. This may be for a variety of reasons and includes copper plating and silver plating
117 of 131
what can reactions at electrodes be represented by?
Reactions at electrodes can be represented by half equations, for example: 2Cl– ➞ Cl2 + 2e– (OXIDATION
118 of 131
what is aluminium manufactured by?
.Aluminium is manufactured by the electrolysis of a molten mixture of aluminium oxide and cryolite.
119 of 131
when does Aluminium form at
Aluminium forms at the negative electrode Al3+ + 3e- Al (reduction) And oxygen at the positive electrode. 2O2- O2 + 4e- (oxidation)
120 of 131
what happens to the negative electrode?
positively charged ions gain electrons (reduction)
121 of 131
what happens to the positive electrode?
negatively charged ions lose electrons (oxidation).
122 of 131
what is OILRIG
123 of 131
production of aluminum using electrolysis- what is the positive electrode made of?
The positive electrode is made of carbon, which reacts with the oxygen to produce carbon dioxide.
124 of 131
why is crylite used in this process
because it lowers the temp at which aluminium oxide melts
125 of 131
electroylysis of sodium chloride- what does The electrolysis of sodium chloride solution produce
hydrogen and chlorine Sodium hydroxide solution is also produced.
126 of 131
these are important....
reagents for the chemical industry, eg sodium hydroxide for the production of soap and chlorine for the production of bleach and plastics.
127 of 131
what happens at the anode
AT THE ANODE Cl- and OH- are attracted Cl- loses 1 electron to form chlorine gas 2Cl- Cl2 + 2e- OXIDATION (OILRIG)
128 of 131
what happens at the cathode
AT THE CATHODE Na + and H + attracted Hydrogen gains 1 electron to form hydrogen gas 2H+ + 2e- H2 REDUCTION (OILRIG)
129 of 131
additional information
The Na+ and OH – , bond together in the electrolyte to make sodium hydroxide NaOH
130 of 131
additional information
Also OH– and H+ ions in the electrolyte which have broken up from water
131 of 131

Other cards in this set

Card 2


what is covalent bonding


covalent bonding is sharing electrons - non-metals only

Card 3


what is ionic bonding


Preview of the front of card 3

Card 4


what is chemical bonding


Preview of the front of card 4

Card 5


what do metals consist of?


Preview of the front of card 5
View more cards


No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all everything resources »