General knowledge - including all definitions Flashcards
(82 cards)
1
Q
Proton Number
A
The
number of protons in the nucleus of an atom
2
Q
Nucleon Number
A
The
total number of protons and neutrons in the
nucleus of an atom
3
Q
Isotopes
A
The same element
which have the same proton number but a
different nucleon number
4
Q
Relative Atomic Mass
A
The average
mass of naturally occurring atoms of an element
on a scale where the 12C atom has a mass of
exactly 12 units
5
Q
Relative Molecular mass
A
The sum
of the relative atomic masses in a molecule
6
Q
Mole
A
1 mol is the amount of substance that contains the same number of particles as there are atoms in 12.0 g of carbon-12
7
Q
Avogadro constant
A
Number of units in one mole of any substance, equal to 6.02214076 × 10^23
8
Q
Electrolysis
A
The breakdown of an ionic
compound, molten or in aqueous solution, by the
passage of electricity
9
Q
Redox
A
It is a reaction in which an element is both oxidized and reduced
10
Q
Oxidizing agent
A
A substance which
oxidizes another substance during a redox
reaction.
11
Q
Reducing agent
A
A substance
which reduces another substance during a redox
reaction.
12
Q
Polymers
A
Large molecules built up from small units
13
Q
Acids
A
Proton donors
When acids dissolve in water to form an aqueous solution, they produce hydrogen ions (H+). These H+ ions make the aqueous solution acidic.
14
Q
Bases
A
Proton acceptor
A base is a substance that can neutralize the acid by reacting with hydrogen ions.
15
Q
Alkali
A
Any base that dissolves in water is called an alkali
16
Q
Atom
A
A particle which can no longer be broken down by chemical means
17
Q
Ions
A
A charged particle which is charged because of an imbalance of protons and electrons
18
Q
Molecules
A
Two or more atoms chemically combined
19
Q
Mixture
A
Two or more substances mixed together but not chemically combined
20
Q
Solute
A
What is being dissolved
21
Q
Solvent
A
What are we dissolving in
22
Q
Solution
A
Solute + solvent = Solution
23
Q
Saturated solution
A
No more solute can dissolve at a given volume and temp of solvent
24
Q
Volatile liquid
A
A liquid which evaporates quickly
25
A pure substance
A substance with no particles of any other substance mixed into it
26
Impurity
An unwanted substance mixed in with the desired substance
27
Methods of separation
Filtration
Crystallization
Evaporation
Simple distillation
Fractional distillation
Paper chromatography
28
Residue and Filtrate
Filtering Chalk and water through filter paper, the chalk would be trapped as residue and the water would go through as a filtrate
29
Rf value
Distance moved by solutes/ Distance moved by solvent
30
Element
An element contains only one type of atom
31
Radioactive
Unstable-nucleus
32
Properties of metals
```
Conduct heat and electricity
Sonorous
High bp and mp
Shiny when polished
Hard and strong
Malleable and Ductile
```
(chemical)
React with oxygen to form basic oxides
Form positive ions
33
Properties of non metals
Do not conduct
Low mp and bp
dull
britlle
(chemical)
React with oxygen to form acidic bases
Form negative ions
34
A compound
Two or more elements chemically combined
35
Signs of chemical change
One or more new substance is formed
Energy is taken in or given out
It is difficult to reverse
36
Allotropes
Two forms of the same element, Diamond and graphite
37
Valency
The number of electrons an atom, gains/loses or shares to form a compound
38
Purity formula
(Mass of pure substance/total substance)x100%
39
Electrolyte
A liquid that contains ions and therefore conducts electricity
40
Uses of chlorine
(yellow-green poisonous)
Plastic PVC
Medical drugs
Bleaches
Hydrochloric acid
Herb/Pesticides
41
Uses of Sodium hydroxide
(corrosive)
Soaps
Detergents
Paper
Medical drugs
42
Uses of hydrogen
Nylon
Hydrogen peroxide
Harden vegetable oils to make margarine
Fuel for hydrogen fuel cells
43
Tests for water
Water will turn
White anhydrous copper (II) sulfate blue
Blue cobalt chloride paper pink
44
Dynamic equilibrium
In a closed system the rate of forward and back reaction of a reversible reaction are equal, meaning no overall change is happening
45
Rate
A measure of change that happens in a single unit of time
46
Noble gases and their uses
Helium-Fills balloons and airships
Argon-Inert atmosphere for lightbulbs, Welding
Neon- Glowing signs
Krypton- Lasers and car headlamps
Xenon- Car headlamps, Hospital lights, light house lights
47
Reactivity series
```
Potassium, K
Sodium, Na
Calcium, Ca
Magnesium, Mg
Aluminum, Al
Carbon, C
Zinc, Zn
Iron, Fe
Lead, Pb
Hydrogen, H
Copper, Cu
Silver, Ag
Gold/Platinum, Au/Pt
```
48
Precious metals
Metals which are rare and scarce such as gold, silver, platinum or palladium.
49
Aluminum Oxide
Bauxite
50
Iron (III) oxide ore
Hematite
51
Zinc sulfide
Zinc Blend
52
Zinc extraction and uses
Zinc blend is roasted in air (to react with Oxygen)
The Zinc oxide formed is the reacted with Carbon monoxide to obtain pure zinc.
Zinc is used in
- Galvanizing
- Sacrificial protection
- Alloys, such as brass and bronze
- Batteries
53
Iron extraction
Coke burns giving out heat and carbon dioxide
Unreacted carbon reacts with carbon dioxide to form carbon monoxide.
Hematite (Iron (III) oxide) is reduced by the Carbon monoxide
Limestone is added, which decomposes into lime and reacts with the impurity sand to form Calcium silicate (slag) that runs off
54
Aluminum extraction and uses
Electrolysis
Bauxite dissolved in molten cryolite to lower mp
Aluminum forms at cathode and runs off
Oxygen formed reacts with carbon anodes to form carbon dioxide. Because of this the carbon anodes must be replaced periodically
Used in
- Aircrafts
- Food/drink containers
- Overhead power cables
- Cooking foil
55
Alloys
```
Brass (copper and zinc)
Mild steel (Iron and carbon[buildings, cars and ships])
Stainless steel (nickel, chromium and steel[cutlery, medical and chemical equipment])
```
56
Fractional distillation of air
Air is first filtered to remove dust, carbon dioxide and water
Compressed and cooled till liquified (condensed)
Nitrogen -196 (top fraction)
Argon -186
Oxygen -183
Krypton -153
Xenon -108 (bottom fraction)
57
Uses of Oxygen
Oxygen masks
Oxygen tents
Reserve for pilots and astronauts
Purifying iron in steel production
58
Uses of Nitrogen
Liquid nitrogen to quick freeze food
Unreactive so used to replace oxygen in food packaging
59
Pollutants
Carbon monoxide
Sulfur dioxide
Nitrogen oxides
Lead
60
Effects of Carbon monoxide and its source
(from incomplete combustion eg in car engines)
| Effect: Binds to hemoglobin in irreversible reaction, leading to death by oxygen starvation
61
Effects of Sulfur dioxide and its source
(fossil fuels)
Effect: Causes respiratory problems and dissolves in rain to from acid rain which eats away at building, statues and can kill plants and fish by lowering the pH of their land or lake/river.
62
Effects of Nitrogen oxides and its source
(heat from car engines causes Nitrogen in air to react with Oxygen in air)[and lightning strikes]
Effect: Causes respiratory problems and causes acidic rain
63
Effects of lead and its source
(petrol)
| Effect- Brain damage for children, Kidney and nervous system issues for adults
64
Rust
Fe2O3.2H2O (rusting is sped up in salt water)
65
Water treatment
Screening traps large particles
Coagulant clumps small particles together
Flotation tanks cause coagulated particles to float and be skimmed off
Sand bed filtration
Charcoal to remove bad tastes and smells
Chlorine to kill microbes
Fluorine added to fight tooth decay
Pumped to reservoir (storage)
66
Haber process
Gasses mixed and scrubbed
Compressed
Passed over Iron catalyst at 450 degrees and 200atm
Cooled ammonia (liquid stored) un reacted gas is recycled
67
Sources of hydrogen
Electrolysis of water
Cracking hydrocarbons
Methane and steam
68
Fertilizers
NPK (nitrogen, phosphorus and potassium)
Ammonium sulfate/Nitrate/phosphate
Potassium sulfate
69
Lead sulfide
Galena
70
Sulfur is found where and in what state?
Found as the element in Mexico, Poland and USA
71
Properties of sulfur
Brittle and yellow
Two allotropes (rhombic and monoclinic)
Low mp
Insoluble in water
reacts with metals to form sulfides
72
Uses of sulfur
Produce sulfuric acid
Vulcanizing (toughening rubber)
Drugs, paper, and pesticides
Cosmetics, shampoo, and lotion
Sulfur concrete which doesn't react with acid (used in acid production factories)
73
Sulfur dioxide properties and uses
Colourless gas heavier than air with a strong chocking smell
Disolves in water to form sulfurous acid (H2SO3)
Acts as bleach when damp or in solution (turns litmus white)
Kills bacteria
Uses:
Production of sulfuric acid
Bleaching wool/ silk/wood pulp for paper
Sterilizing agent used in making soft drinks/ jams/ dried fruit
74
Contact process
Sulfur burned in air to get Sulfur dioxide
Passed over Vanadium (V) oxide at 450 degrees and 2 atm to form Sulfur trioxide(SO3)
Dissolved in conc H2SO4 to form oleum
Mixed carefully with water to form H2SO4
75
Uses of sulfuric acid
(corrosive)
Plastics and fibers
Soaps and detergents
Fertilizers such as ammonium sulfate
Paints and pigments
76
Water to acid or acid to water?
Acid to water always, as water to acid is highly exothermic and could burn you if splashed
77
Concentrated Sulfuric acid
Dehydrating agent which removes all Hydrogen and oxygen form sugar molecules leaving only black carbon
Mixed with water, highly exothermic
78
Limestone uses
```
[CaCO3]
(Crushed)
Extracting iron from hematite
Road building
Chips for concrete
```
(powdered)
Neutralize acidity in soil
Desulfurization
(heated with clay)
Cement
79
Lime
[CaO (by thermoly decomposing limestone)]
Making steel from iron
Neutralize acidic soil
Drying agent
80
Slaked lime
[Ca(OH)2] Lime + water
Neutralize acidic soil and lakes
Desulfurization
81
Limestone in a kiln
Limestone is heated in a rotary kiln with a fan blowing through the kiln to blow away carbon dioxide which would otherwise react with the Calcium Oxide to form Limestone again
82
Flue gas desulferization
SO2 coming out of the chimney (flue) at power stations reacts with Calcium Hydroxide to form calcium sulfate that is then turned into gypsum (hydrated calcium sulfate) by reacting with oxygen and water
SO2 + Ca(OH)2 ---> CaSO3 +H2O
2CaSO3 + H2O + 4O2 ---> 2CaSO4.2H2O
