chemistry Flashcards
(62 cards)
1
Q
acid + metal becomes…
A
salt + hydrogen gas
2
Q
acid + metal hydroxide becomes…
A
salt + water
3
Q
acid + metal oxide becomes…
A
salt + water
4
Q
acid + metal carbonate becomes…
A
salt + water + carbon dioxide
5
Q
acid + metal hydrogen carbonate
A
salt + water + carbon dioxide
6
Q
Strong acids
A
Will always ionise 100% of the molecules to become H+ ions
7
Q
Weak acids
A
Ionise less than 100% of the molecules into H+ ions
8
Q
rate of reaction equation
A
9
Q
How to find average rate of reaction
A
Gradient between 2 points
10
Q
How to find instantaneous rate of reaction
A
Gradient of a tangent of a point
11
Q
Concentrated acids
A
High amount of the substance in a set volume
12
Q
Dilute acids
A
Small amount of substance in a set volume
13
Q
Collision theory
A
Reactant particles need to collide, when they collide, they need to:
- Be in the correct orientation
- Have enough energy (activation energy) to break apart bonds
14
Q
Ways to change the rate of reaction
A
- Concentration
- Temperature
- Surface area
- Catalyst
15
Q
How does increasing concentration change the rate of reaction
A
- More particles in a given volume
- Increases the frequency of successful collisions
16
Q
How does increasing temperature change the rate of reaction
A
- Increases the kinetic energy of the particles (moving around faster so have more activation energy)
- Increases the frequency of successful collisions
17
Q
How does increasing surface area change the rate of reaction
A
- Increases the surface area that reactants react with
- Increases the frequency of frequent successful collisions
18
Q
How does adding a catalyst change the rate of reaction
A
- Breaks/ weakens the bonds of reactants but does not get used in reaction
- Rearranges particles to be in correct orientation
19
Q
Catalyst definition
A
A substance that is added to speed up the rate of reaction without being a part of the chemical reaction
20
Q
Properties of acids
A
- Produce hydrogen ions when dissolved in water
- Sour in taste
- Molecular in structure
- Dissolves substances
21
Q
Properties of bases
A
- Produces hydroxide ions when dissolved in water
- Feels soapy
- Alkaline
22
Q
0-6 on the pH scale is…
A
Acidic
23
Q
8-14 on the pH scale is…
A
Basic
24
Q
Electron definition
A
- Negative charge
- Smaller than protons and neutrons
- Sit in the shells of an atom
25
Protons
- Have a positive charge
26
Neutrons
- Have a neutral charge
27
Nucleus
- Centre of the atom
- Has a positive charge
- Contains protons and neutrons
28
What are ions?
- A version of an atom that becomes charged through gaining or losing electrons
- Its goal is to have a full outer shell
29
Cations
- Positively charged ions (more protons than electrons)
- Mostly metals
30
Anions
- Negatively charged ions (more electrons than protons)
- Mostly non-metals
31
Polyatomic ions
OH(-): Hydroxide
CO3(2-): Carbonate
HCO3(2-): Hydrogen carbonate
32
Ionic bonding
The bonding between a metal and a non-metal through the transfer of electrons
33
Displacement reactions
A displacement reaction occurs when the more reactive metal is placed into a solution with a less reactive metal
34
Reactivity series of elements (from most to least)
Potassion, Sodium, Calcium, Lithium, Magnesium, Aluminium, Zinc, Iron, Tin, Lead, Copper, Gold
35
Properties of ionic compounds
- Lattice structure alternating between cations and anions
- High melting and boiling points
- Crystalline solids
- Conducts electricity when in molten or aqueous state
- Hard
- Brittle
36
What is shown by the periods on the periodic table?
- Horizontal rows
- Indicate the number of shells occupied by electrons
37
What is shown by the groups on the periodic table?
- Vertical columns
- Indicate the number of valence electrons that are in the atom
38
Metallic bonding
Bonding between metals, through electrostatic attraction between delocalised electrons and metal cations.
39
Properties of metallic compounds:
- Good conductors of heat and electricity
- High melting and boiling points
- Malleable
- Ductile
- High density
- Lustrous
40
Covalent bonding
- Occurs between 2 non-metals
- Electrons are 'shared' between atoms so they have a full outer shell
- Can join two or more elements with covalent bonding
41
Atomic number
Indicates the number of protons (and electrons) in an atom
42
Mass number
Indicates the number of protons and neutrons in an atom
43
Types of heat treatment of metals
- Annealing
- Quenching
- Tempering
44
Annealing
- Heated until red hot, called slowly
- Large crystals with small gaps
- Softer, more ductile
45
Quenching
- Heated until red hot, cooled quickly in cold water
- Small crystals, more gaps
- Harder but more brittle
46
Tempering
- Quenched, then warmed to lower temperature, cooled slowly
- Reduces brittleness
- Remains hard
47
Law of conservation of mass
Atoms cannot be created or destroyed
48
Why do ionic compounds have high melting and boiling points?
- Large amounts of energy required to break electrostatic attraction between oppositely charged ions (strong ionic bonds)
49
Why do ionic compounds have crystalline solids?
- Due to their regular, repeating arrangement of ions known as an ionic lattice
50
Why do ionic compounds conduct electricity when aqueous or molten?
- To conduct electricity, particles muct be charged and free-moving
- When solid, the ions are trapped in the lattice structure (not free-moving)
- BUT in a molten or aqueous state, the positive and negative ions are free to move in a uniform way towards electricity
51
Why are ionic compounds hard?
- The surface of ionic compounds is not easily scratched as a strong force is needed to disrupt the ionic bonding
52
Why are ionic compounds brittle?
- When enough force is applied to distort the ionic lattice, ions of like charge become adjacent, repel and cause the ionic lattice to shatter
53
Why are metals good conductors of electricity?
- Delocalised electrons are free to move to the positive electrode
- Are attracted due to their opposite charges
54
Why are metals good conductors of heat?
- Heat causes the cations and electrons to vibrate more rapidly
- Delocalised electrons move through the lattice, passing heat on
55
Why are metals malleable and ductile?
- A force can push petal ions past each other as the sea of delocalised electrons holds the layers together
56
Why are metals lustrous?
- Delocalised electrons reflect photons of light
57
Why do metals have high melting and boiling points?
- Strong electrostatic bonds require large amounts of energy to break
58
Why do metals have high density?
- A lot of mass in a small volume
- Cations are very close together
59
Ways to extract metals
- Mining
- Roasting in air
- Smelting
- Electrolysis
60
Electrolysis
- Using electrodes to collect the metal cations on the negative terminal
61
Roasting in air
- Heating metal to a high temperature below melting point in the presence of air
62
