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Is exothermic negative or positive
Negative
What are the standard conditions of enthalpy change
100kPa, 298K and 1moldm-3
Is endothermic positive or negative
Positive
What is the definition of standard enthalpy of reaction
Enthalpy change when a reaction occurs in molar quantities from the equation, under standard conditions with all reactants and products in their standard states
What is the definition of standard enthalpy of formation
The enthalpy change when one mole of a compound is formed from its elements under standard conditions with all reactants and products in their standard states
What is the definition of standard enthalpy of combustion
The enthalpy change when one mole of a substance is completely burned in oxygen under standard conditions with all reactants and products in their standard states
Define standard enthalpy of neutralisation
The enthalpy change when an acid and a base react to form one mole of water under standard conditions, with all reactants and products in standard states
What’s the maths equation for when your measuring enthalpy changes using calorimetry and give the units of all the letters
Q=mc x change in t
M is mass of the substance being heated in g
C is the specific heat capacity
Change in t is temp change in k or degrees
Q is the heat energy in J
What’s the maths equation you use after Q=mc x change in t
Change in H= Q/n
Q is the answer to the other equation in J
Change in H is in J
N is moles
What are some experimental errors that can happen during calorimetry
Heat loss to surroundings, incomplete combustion and evaporation of fuel
Define Hess’s law
The total enthalpy change for a reaction is independent of the route taken
Define bond enthalpy
Energy needed to break 1 mole of a bond in a gaseous molecule
Define mean bond enthalpy
Average energy needed to break a type of bond across different molecules
What’s the maths equation for bond enthalpies
Change in H= the sum of reactants - the sum of the products
