1
Q
What is enthalpy change?
A
The heat energy released or absorbed per mole in a reaction.
2
Q
+ sign means what in enthalpy change?
A
Heat is absorbed: endothermic. The temperature of the surroundings (thermometer) goes down.
3
Q
”-“sign means what in enthalpy change?
A
Heat is released: exothermic. The temperature of the surroundings (thermometer) goes up.
4
Q
What unit is enthalpy change?
A
kJ/mole
5
Q
What does enthalpy change rely on?
A
The balance between:
- breaking bonds, which absorbs energy
- making bonds, which releases energy
6
Q
What is an energy level diagram?
A
A way of representing enthalpy change.
Chemistry
flashcards
Decks in class (59)
# Cards
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Solubility rules9
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3.1.1 Introduction9
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3.1.2 Elements7
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3.1.3 Compounds6
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3.1.4 Solutions11
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3.2.1 Particle numbers14
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3.2.2 Electrons3
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3.3.1 Ion formation7
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3.3.2 Ionic Formulae11
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3.3.3 Ionic structure and bonding3
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3.3.4 Ionic Properties6
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3.4.1 pH and Indicators22
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3.4.2 Oxygen and Oxides18
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3.4.3 Acids, bases and alkalis22
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3.4.4 Acid + Base reaction5
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3.4.5 Making soluble salts3
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3.4.6 Acid + Carbonate reaction6
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3.4.7 Making insoluble salts3
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3.5.1 Metal Structure: bonding and properties10
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3.5.2 Metal Carbonate decomposition4
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3.5.3 Metal + Water/Steam reaction18
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3.5.4 Acid + Metal reaction8
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3.5.5 Metal Displacement reactions2
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3.5.6 Metal extraction9
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3.5.7 Iron, Steel and other metals20
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4.1.1 Covalent Bonding6
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4.1.2 Simple Molecular substances5
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4.1.3 Giant Covalent substances11
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4.1.4 Bonding summary9
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4.2.1 Group 7 elements23
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4.2.2 Halogen displacements3
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4.3.1 Collision Theory8
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4.3.2 Effect of Concentration and Pressure4
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4.3.3 Effect of Surface Area3
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4.3.4 Effect of Temperature3
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4.3.5 Effect of Catalysts2
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4.4.1 Relative formula mass2
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4.4.2 Moles2
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4.4.3 Mole ratios in formulae7
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4.4.4 Mole ratios in equations8
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4.5.1 Crude oil14
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4.5.2 Alkanes25
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4.5.3 Cracking3
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4.5.4 Alkenes10
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4.5.5 Addition polymers10
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4.6.1 Gas tests7
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4.6.2 Cation tests13
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4.6.3 Anion tests9
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4.6.4 Chromatography4
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5.1.1 Gas volumes1
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5.1.2 Concentration calculations2
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5.1.3 Titration3
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5.2.1 Enthalpy changes6
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5.2.2 Bond breaking and making6
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5.2.3 Calorimetry6
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5.3.1 Alcohols21
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5.3.2 Carboxylic Acids9
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5.3.3 Esters8
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5.3.4 Polyesters6
