Question

1- Given the equation (the arrow should be two directional), 2 SO2(g) + O2(g) ↔ 2 SO3(g), if the activities of O2, SO3 and SO2 are respectively 0.019, 0.00019 and 0.01939, what is the value of K?

A.

5200

B.

0.00020

C.

none

D. 5100

2-We can simplify an equilibrium position calculation from equilibrium constant by assuming the reactant concentration changes very little,so long as the change in reactant is _________ of the original concentration.

A.=5%

B.≤ 5%

C.NONE

D. ≥5

3. Given an equilibrium process of A forming 2B, with initial molarities of 0.908 M A and 0.000 M B, if the equilibrium constant for the reaction is 0.0290, what are the respective concentrations of A and B at equilibrium?

A.

0.830 M A, 0.155 M B

B.

0.0776 M A, 0.155 M B

C.

none

D. 0.830 M A, 0.0776 M B

4. We can determine the equilibrium concentrations of a reaction from its equilibrium constant by using a process referred to as a(n) __________ table.

A.

net change

B.

equilibrium

C.

none

ICE

5. For any given system at constant temperature, the number of possible equilibrium positions is ____________.

	A.	five
	B.	one
	C.	three
	D.	infinite

Answer 1

2 SO₂(g) + O₂(g) ↔ 2 SO₃(g)

Kc = [SO3]² / [SO₂]²[O₂]

[ ] denotes activity of any species

Kc = [0.00019]² / [0.01939]²[0.019] = 0.005053 = 5.05 x 10^-3

1.C none

2.

b) if error is less than or equal to 5 % or <= 5%

3.

A <---->2B

Kc = [B]²/[A]

make ICE table

A B

initial 0.908 0

change -x +x

equilibrium 0.908-x +x

Kc = [x]²/[0.908-x]

0.0290 = x² / 0.908-x

0.026332 -0.0290x = x²

solving this we get:

x1 = 0.1484179

x2 = -0.1774 rejected as x concentration cannot be neagative

A = 0.908 - 0.148 = 0.76

B = 0.148

c) none

4.

ICE

5.

an equilibrium has two degree of freedom

temperature and pressure

when temperature is fixed only degree of freedom is pressure

hence (b) one

** activities of O2, SO3 and SO2 are respectively 0.019, 0.00019 and 0.01939

please confirm the ** line once