Thermochemistry

Question 1

1st law of thermodynamics is based on

Answer 1

Law of conservation of energy

Question 2

delta H = ?

Answer 2

deltaU + delta(ng)RT

Question 3

deltaHF in terms of Hfproducts and Hfreactants

Answer 3

deltaHf products - deltaHfreactants

Question 4

deltaHF in terms of BDEproducts and BDEreactants

Answer 4

deltaHf = (BDE)reactants - (BDE)products

Question 5

delta S = ?

Answer 5

qrev/T
(inversely proportional to T but S id directly proportional to T)

-deltaHreaction/T

Question 6

Reversible isothermal expansion of ideal gas(delta U and deltaS)

Answer 6

delta U = 0

delta S equal to 0

Question 7

Irreversible isothermal expansion of ideal gas(delta U and deltaS)

Answer 7

delta U = 0

delta S not equal to 0

Question 8

Heat capacity extensive or intensive

Answer 8

Extensive

Question 9

Molar heat capacity extensive or intensive

Answer 9

Intensive

Question 10

Standard enthalpy of atomization

Answer 10

Enthalpy change when one mole of atom is obtained from its molecular form

Question 11

Enthalpy of solution(meaning and formula)

Answer 11

Enthalpy change when one mol of subst dissolves in specific amt of solvent
deltaHsol = deltaHlattice + deltaHhydration
+ve deltaHsol means endothermic, i.e not very soluble

Question 12

For equilibrium comment of entropy

Answer 12

Entropy is maximum

deltaEntropy = 0

Question 13

G =

Answer 13

H-TS

Question 14

At eq comment on deltaG

Answer 14

deltaG = 0