Biological & Chemical Reactions Driving

Question 1

Spontaneous Reactions

Answer 1

Reactants are converted to product independent of external triggers. Happen of their own accord

Question 2

Thermodynamics

Answer 2

Measure of whether a reaction will be spontaneous. Components: enthalpy (changes in heat) and entropy (changes in disorder)

Question 3

Enthalpy Outline

Answer 3

Change in heat energy of a reaction (diff between reactants and products). Units: kJ/mol

Question 4

Exothermic Reaction

Answer 4

Products have less heat energy then reactant, heat given out to atmosphere. Surroundings heat up

Question 5

Endothermic Reaction

Answer 5

Products have more energy then reactants, energy taken in from atmosphere. Surroundings cool

Question 6

Heat Pack Mode of Action

Answer 6

Heat pad is mashed break internal bag separating CaCl2 from water. Water and CaCl2 react exothermically giving out heat to surroundings. Used to gtreat sore muscle and arithic pain

Question 7

Cold Pack Mode of Action

Answer 7

Mashed to break internal bag separating NH4NO3 from water. NH4NO3 reacts with water endothermically, cooling surroundings. Treat swellings and sprains

Question 8

Calorimetry Def

Answer 8

Measure of change of heat energy during reaction

Question 9

Standard Conditions of Heat

Answer 9

298 K

Question 10

Standard conditions of Pressure

Answer 10

1 atm

Question 11

Standard Enthalpy Change of Formation (f0

Answer 11

Heat change when 1 mole of a compound is formed from it’s uncombined elements at 298 K and 1 atm

Question 12

Standard Enthalpy Change of Combustion (c0)

Answer 12

Change of energy 1 mole of a compound is burned in excess oxygen at 298 K and 1 atm. Always highly exothermic

Question 13

Standard Enthalpy Change of Reaction (rxn0)

Question 14

1st Law of Thermodynamics

Answer 14

Energy can neither be created nor destroyed but can pass from one form to another

Question 15

2nd Law of thermodynamics

Answer 15

Any system, of it’s own accord, will react to increase it’s entropy

Question 16

3rd law of thermodynamics

Answer 16

Only a perfectly ordered system will have 0 entropy eg a crystalline solid at 0K

Question 17

Hess’ Law

Answer 17

Enthalpay of a reaction is the same regardless of pathway reaction occurs by (done in 1 step or multiple)