Topic 5 Test Review

Question 1

standard states

Answer 1

298K
1.00 x10⁵ Pa

Question 2

standard enthalpy change of formation (ΔHf)

Answer 2

the enthalpy change that results when one mole of a compound is formed from its elements (in their standard states)

Question 3

temperature

Answer 3

average kinetic energy of molecules

Question 4

heat

Answer 4

amount of energy exchanged due to temperature difference between two substances (higher temp.<–> lower temp.)

Question 5

enthalpy change

Answer 5

The change in internal (chemical) energy (H) in a reaction
(the enthalpy itself cannot be measured so we measure the change instead)
ΔH exothermic = (-)
ΔH endothermic = (+)
STABILITY
exothermic < endothermic

Question 5

exothermic

Answer 5

((-)ΔH) heat energy transferred from system to surroundings ⁻⁻|_

Question 6

endothermic

Answer 6

((+)ΔH) system takes energy from surroundings _|⁻⁻

Question 7

common experimental errors

Answer 7

• heat loss to the environment
• incoplete combustion

Question 8

surrounding vs system

Answer 8

the surrounding is everything the system is NOT

Question 9

ΔHBE ; ΔHc ; ΔHf

Answer 9

bond enthalpy/energy; combustion enthalpy; formation enthalpy

Question 10

specific heat capacity and density of water

Answer 10

4.18 Jg⁻¹k⁻¹ ; 1.00 g/cm³

Question 11

bond energy

Answer 11

amount of energy required to break a bond. (endothermic (+)) (kJ/mol)

Question 12

calculating ΔHrxn in terms of ΔHf

Answer 12

(ΔHf of products) - (ΔHf of reactants)

Question 13

calculating ΔHrxn in terms of ΔHBE

Answer 13

(ΔHBE of reactants) - (ΔHBE of products)

Question 14

ºC —> K

Answer 14

+ 273

Question 15

n = CV

Answer 15

moles = concentration * volume

Question 16

calculating ΔHrxn in terms of ΔHc

Answer 16

(ΔHc of reactants) - (ΔHc of products)

Question 17

Percentage Difference Formula

Answer 17

(Exp - Lit)/Lit *100