10 (easy)

Question 1

Concentration change (1)

Answer 1

1. (Reaction), Concentration of _ increase/decrease, ep shift to _

Question 2

Pressure change (2)

Answer 2

1. Num of moles of gaseous reactants >=< num of moles of gaseous products
2. Increase/decrease in pressure, ep shift _

Question 3

Temperature change (3)

Answer 3

1. Increase in pressure favors endothermic reaction/ decrease in pressure favors exothermic reaction
2. Forward reaction is _
3. Increase/ decrease in temp cause ep to shift to _

Question 4

Why catalyst no effect on ep?

Answer 4

Catalysts increase forward and backward reactions to the same extent

Question 5

Temperature changes on Kc (4)

Answer 5

1. Increase in temp favors endo reaction/ decrease in temp favors exo
2. Forward reaction is endo/exo
3. Increase/decrease in temp causes ep to shift to _
4. Kc increases/decreases when temp increases/decreases

Question 6

Le Chatelier’s principle

Answer 6

if reaction conditions of a system in eqm is changed, the ep of the system will shift in a way to reduce effect of the change

Question 7

Add water case (solvent)

Answer 7

1. Concentration of both products and reactants decease
2. (Write Qc)
3. The numerator(分子)/denominator decreases to a greater extent than the denominator/numerator, Qc increases/decreases
4. Thus Qc<>Kc
5. Ep shifts _
6. More _ is formed, (observation)

Question 8

Constant (l/s)

Answer 8

1. Conc of _ is a constant
2. Addition of _ does not affect conc of _, conc of all species in eqm system rains unchanged
3. There is no effect on ep
4. No obv change

Question 9

Why use this color indicator?

Answer 9

-> pH range of color change falls on the steepest part of the titration curve

Question 10

Deduce exo/endo:

Answer 10

1. When temp increases/decreases, conc of _ increases/decreases
2. Implying ep shift _
3. As increase in temp favors _ rxn, forward rxn is _

Question 11

chemical bonding: (exo/endo)

Answer 11

1. The reaction involves breaking/forming of _ bond, hence rxn is endo/exo

Question 12

TEMPERATURE have thermal contraction/expansion

Question 13

Why is water neutral at all temperature?

Answer 13

as concentration of H+(aq) and OH-(aq) are the same

Question 14

Why is Haber process (make NH3) a slow reaction?

Answer 14

a lot of energy is needed to break strong NN in N2 molecules and H-H bonds in H2 molecules

Question 15

Why isn’t high pressure needed in contact process (remains at 1 atm)?

Answer 15

as the rate of conversion is already very high increasing pressure can only lead to small increase in percentage conversion but very high cost needed

Question 16

Contact process equations

Answer 16

S + O2 -> SO2
2SO2 + O2 REVERSIBLE 2SO3
SO3 + H2SO4 -> H2S2O7
H2S2O7 + H2O -> 2H2SO4

Question 17

What is dynamic equilibrium

Answer 17

rate of forward reaction equal to rate of backward reaction but not zero

Question 18

Definition of Irreversible reaction

Answer 18

proceeds in one direction and goes to completion

Question 19

Definition of reversible reaction

Answer 19

proceeds in either direction and never goes to completion