All definitions in Chem Flashcards

1
Q

Salt

A

(An ionic compound consisting of a cation such as a metal ion or an ammonium ion from a base and an anion from an acid)
A compound formed when the hydrogen ion in an acid is replaced by a metal ion or an ammonium ion

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

Recrystallisation

A

Carried out to obtain pure crystals of the salt from its solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

Titration

A

Carried out to determine the exact volume of an acid needed to neutralise a fixed volume of an alkali solution with the help of an indicator

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

Crystallisation

A

Carried out to obtain crystals of the salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

Double decomposition method

A

Two aqueous solutions of two different soluble salts are mixed together to form the insoluble salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

Precipitate

A

A solid substance formed during a reaction occurring in a solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

Qualitative analysis

A

A chemical technique used to identify the ions present in a salt by analysing its physical and chemical properties and hence determine the identity of salt

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

Electrolytes

A

Substances that can conduct electricity either in the molten state or in an aqueous solution and undergo chemical changes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

Non-electrolytes

A

Substances that cannot conduct electricity either in the molten state or in an aqueous solution

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

Conductors

A

Substances that can conduct electricity in the solid or molten state but are not chemically changed
Hence, conductors are not electrolytes

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Ionic compound

A

Do not conduct electricity in the solid state because the ions are held in a lattice and do not move freely

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Covalent compound

A

Exist as molecules in an organic solvent, do not conduct electricity in an organic solvent such as methylbenzene

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

Electrolysis

A

A process whereby a compound is decomposed into its consistuent elements when an electric current passes through an electrolyte

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

Electrode

A

A conductor in the form of a wire, rod or plate which carries electric current in and out of the electrolyte during electrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

Active electrode

A

An electrode which takes part in chemical reactions during electrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
16
Q

Inert electrode

A

An electrode which does not take part in chemical reactions during electrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
17
Q

Aqueous solution

A

A solution produced when the compound is dissolved in water

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
18
Q

Electroplating

A

A process of depositing a layer of metal on another substance using electrolysis

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
19
Q

Voltaic cell

A

aka galvanic cell

A device which converts chemical energy to electrical energy

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
20
Q

Anode

A

The electrode where the process of donation of electrons takes place
In electrolysis, the anode is positively charged
In a voltaic cell, the anode is negatively charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
21
Q

Cathode

A

The electrode where the process of acceptance of electrons take place
In electrolysis, the anode is negatively charged
In a voltaic cell, the anode is positively charged

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
22
Q

Insoluble salts

A

Formed as a precipitate when two aqueous solutions of two different soluble salts are mixed together

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
23
Q

Electrochemical series

A

An arrangement of metals based on the tendency of each metal atom to donate electrons

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
24
Q

Metal displacement reaction

A

A metal is situated at a higher position in the electrochemical series is able to displace a metal below it in the series from its salt solution
(This happens because metals with higher positions have a greater tendency to form positive ions)

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
25
Q

Acid

A

A substance which dissociates in water to produce hydrogen ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
26
Q

Hydroxonium ion

A

The hydrogen ion that attaches itself to a water molecule

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
27
Q

Monoproctic acid

A

An acid that contains only one ionisable hydrogen atom, producing only one hydrogen ion per molecule of acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
28
Q

Polyprotic acid

A

An acid that can produce more than one hydrogen ion per molecule of acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
29
Q

Basicity

A

The number of ionisable hydrogen atoms per molecule of acid

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
30
Q

Acidic oxides

A

Non-metal oxides which react with water to produce acidic solutions which contain hydrogen ions

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
31
Q

Mineral acids

A

Obtained from minerals

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
32
Q

Organic acids

A

Extracted from animal and plant materials

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
33
Q

Base

A
  1. A substance which ionises in water to produce hydroxide ions
  2. A substance that reacts with an acid to form a salt and water only
34
Q

Ionic bases

A

Consists of metal oxides and metal hydroxides

35
Q

Alkali

A

A base that is soluble in water and ionises to produce hydroxide ions

36
Q

Acidity

A

A measure of the concentration of the hydrogen ions in the solution

37
Q

Alkalinity

A

A measure of the concentration of the hydroxide ions in the solution

38
Q

Degree of dissociation

A

The amount or percentage of dissociation

Measures the percentage of acid molecules that ionises when dissolved in water

39
Q

Strong acid

A

Completely ionised in water to produce a high concentration of hydrogen ions

40
Q

Weak acid

A

Partially ionised in water to produce a low concentration of hydrogen ions

41
Q

Strong alkali

A

Completely ionised in water to produce a high concentration of hydroxide ions

42
Q

Weak alkali

A

Partially ionised in water to produce a low concentration of hydroxide ions

43
Q

Solution

A

A mixture formed by dissolving a solute in a solvent

44
Q

Molarity

A

The number of moles of solute present in 1 dm-3 of solution

45
Q

Standard solution

A

A solution whose concentration is accurately known

46
Q

Titration

A

A very useful laboratory technique in which one solution is used to analyse another solution

47
Q

End point

A

The point in the titration at which the indicator changes colour

48
Q

Rate of reaction

A

(Measures the speed at which the reactants are converted to the products in a chemical reaction)

The change in a selected quantity during a reaction per unit time

49
Q

Instantaneous rate of reaction

A

The rate of the reaction at a given time

50
Q

Catalyst

A

A substance which can alter the rate of a chemical reaction while itself remains chemically unchanged at the end of the reaction

Can be classified into positive catalysts and negative catalysts (inhibitors)

51
Q

Positive catalyst

A

A catalyst that increases the rate of reaction

52
Q

Negative catalyst

A

A catalyst that decreases the rate of reaction

53
Q

Haber process

A

An industrial process to manufacture ammonia on a large scale

54
Q

Ostwald process

A

An industrial process to manufacture nitric acid on a large scale

55
Q

Contact process

A

An industrial process to manufacture sulphuric acid on a large scale

56
Q

Frequency of effective collision

A

The number of effective collisions per second

57
Q

Thermochemistry

A

The study of changes in heat energy during chemical reactions

58
Q

Exothermic reaction

A

A chemical reaction that gives out heat to the surroundings

59
Q

Endothermic reaction

A

A chemical reaction that absorbs heat from the surroundings

60
Q

Heat of reaction

A

The amount of heat energy released or absorbed during a chemical reaction

61
Q

Energy level diagrams

A

Used to show the energy content of chemicals before and after a reaction

62
Q

Thermochemical equation

A

A balanced chemical equation that also contains its heat of reaction on the right side of the equation

63
Q

Heat of precipitation

A

The heat change when one mole of a precipitate is formed from its ions in aqueous solution under standard conditions

64
Q

Heat of displacement

A

The heat change when one mole of metal is displaced from its salt solution by a more electropositive metal

65
Q

Heat of neutralisation

A

The heat produced when one mole of water is formed from the reaction between an acid and an alkali

66
Q

Heat of combustion

A

The heat produced when one mole of a substance is completely burnt in oxygen under standard conditions

67
Q

Bomb calorimeter

A

To determine the heat of combustion of fuel accurately

68
Q

Inexhaustible

A

Unable to use up because existing in abundance

69
Q

Intermittent

A

Not happening regularly or continuously

70
Q

Matter

A

Anything that occupies space and has mass

71
Q

Compound

A

A substance that contains two or more elements that are chemically bonded together

72
Q

Atom

A

The smallest particle of an element that can participate in a chemical reaction

73
Q

Molecule

A

A neutral particle that consists of two or more atoms which are chemically bonded together

74
Q

Compound

A

A substance that contains two or more elements that are chemically bonded together

75
Q

Ion

A

A postively-charged or negatively-charged particle

76
Q

Diffusion

A

Occurs when the particles of a substance move between the particles of another substance from a region of high concentration to a region of low concentration

77
Q

Proton number

A

The number of protons in its atom

78
Q

Nucleon number / Mass number

A

The total number of protons and neutrons in its atom

79
Q

Isotopes

A

Atoms of the same element with the same number of protons but different numbers of neutrons

80
Q

Valence electrons

A

Electrons found in the outermost occupied shell of an atom