energetics

Question 1

standard enthraphy change

Answer 1

heat energy transferred under standard conditions

Question 2

standard enthraphy change of reaction

Answer 2

the enthrapy change that accompanies the reaction with molar quantities shown in the equation

Question 3

standard enthrapy of formation

Answer 3

the enthraphy change when one mole of a compound is formed from its elements (standard conditions, reactants in standard states)

Question 4

standard enthrapy of combustion

Answer 4

the enthrapy change when one mole of substance reacts completely with oxygen (standard conditions, reactants at standard states)

Question 5

standard enthrapy of neutralisation

Answer 5

the enthrapy change when an acid and a base react to form one mole of H2O(l) (standard conditions, reactants at standard states)

Question 6

what is the equation for heat energy change

Answer 6

q=m.c./\T

Question 7

what does the equation q=m.c./\T calculate?

Answer 7

heat energy change

Question 8

experimental method for calculating standard enthrapy of neutralisation

Answer 8

• measure out reactants separatly
• place one reactant in a polystyrene cup
• measure initial temperature using a thermometer
• mix in other reactant
• record maximum temperature
• calculate enthrapy change (always negetive)

Question 9

experimental method for calculating enthrapy of combustion

Answer 9

• add known volume of water into calorometer
• record initial temperature
• weigh spirit burner (with lid and alcohol)
• light spirit burner
• burn alcohol until the temperature of the water rises by 20°c
• record final temperature of water
• calculate enthrapy change

Question 10

Hess’ law

Answer 10

the enthrapy change of a chemical reaction I’d independent if the way in which the reaction is brought about. It only depends in the initial and final states