AS Calculations and Enthalpy

?
  • Created by: leenaq
  • Created on: 08-04-14 18:26
What is a mole?
The amount of substance that has as many single particles as there are atoms in exactly 12g of a carbon-12 isotope
1 of 20
What is the definition of relative atomic mass?
The average mass of an atom of an element compared with one-twelfth the mass of an atom of carbon-12
2 of 20
What is the definition of relative isotopic mass?
The mass of an elements' isotope on a scale where an atom of carbon-12 is 12
3 of 20
What is the definition of relative molecular mass?
The average mass of a compounds' molecule compared with one-twelfth the mass of an atom of carbon-12
4 of 20
What is the equation for the number of moles (using particles)?
No. of particles you have / No. of particles in a mole
5 of 20
What is the equation for the number of moles (using mass)?
mass of substance(s) / molar mass
6 of 20
What is the equation for the number of moles in concentration?
concetration x volume (cm3) / 1000 or concentration x volume (dm3)
7 of 20
What is the equation for the number of moles in gas volume?
volume in dm3/ 24 or volume in cm3/ 24000
8 of 20
Enthalpy change (∆H) is...
The heat energy transferred in a reaction at constant pressure
9 of 20
Do exothermic reactions release or absorb energy?
Releases energy, the ∆H is negative
10 of 20
Do endothermic reactions release or absorb energy?
Absorbs energy, the ∆H is positive
11 of 20
What is the activation energy?
The minimum amount of energy needed to begin breaking reactant bonds and start a chemical reaction
12 of 20
Enthalpy change is affected by two things which are?
Temperature and pressure
13 of 20
What are the standard conditions?
Pressure of 100kPa, Temperature of 298K or (25C), Concentration of 1 mol dm-3, Standard state the physical state of the substance in the standard temperature
14 of 20
What is the definition of the standard enthalpy change of reaction?
the enthalpy change when the reaction occurs in molar quantities represented in a chemical equation
15 of 20
What is the definition of the standard enthalpy change of formation?
The enthalpy change when 1 mole of a compound is formed from its elements
16 of 20
What is the definition of the standard enthalpy change of combustion?
The enthalpy change when 1 mole of a substance is completely burned in oxygen
17 of 20
What is the definition of the standard enthalpy change of neutralisation?
The enthalpy change when 1 mole of water is formed from the neutralisation reaction of hydrogen and hydroxide
18 of 20
What is the definition of the standard enthalpy change of reaction?
The enthalpy change when 1 mole of an element is converted to gaseous atoms
19 of 20
Hess's Law states that...
The total enthalpy change of a reaction is always the same, no matter which route is taken
20 of 20

Other cards in this set

Card 2

Front

What is the definition of relative atomic mass?

Back

The average mass of an atom of an element compared with one-twelfth the mass of an atom of carbon-12

Card 3

Front

What is the definition of relative isotopic mass?

Back

Preview of the front of card 3

Card 4

Front

What is the definition of relative molecular mass?

Back

Preview of the front of card 4

Card 5

Front

What is the equation for the number of moles (using particles)?

Back

Preview of the front of card 5
View more cards

Comments

No comments have yet been made

Similar Chemistry resources:

See all Chemistry resources »See all Enthalpy resources »