<< Chapter < Page Chapter >> Page >

For a precipitation reaction to be useful in a gravimetric analysis, the product of the reaction must be insoluble. Is K c >1,<1, or ≈ 1 for a useful precipitation reaction?

Got questions? Get instant answers now!

Write the mathematical expression for the reaction quotient, Q c , for each of the following reactions:

(a) CH 4 ( g ) + Cl 2 ( g ) CH 3 Cl ( g ) + HCl ( g )

(b) N 2 ( g ) + O 2 ( g ) 2 NO ( g )

(c) 2 SO 2 ( g ) + O 2 ( g ) 2 SO 3 ( g )

(d) BaSO 3 ( s ) BaO ( s ) + SO 2 ( g )

(e) P 4 ( g ) + 5 O 2 ( g ) P 4 O 10 ( s )

(f) Br 2 ( g ) 2 Br ( g )

(g) CH 4 ( g ) + 2 O 2 ( g ) CO 2 ( g ) + 2 H 2 O ( l )

(h) CuSO 4 · 5 H 2 O ( s ) CuSO 4 ( s ) + 5 H 2 O ( g )

(a) Q c = [ CH 3 Cl ] [ HCl ] [ CH 4 ] [ Cl 2 ] ; (b) Q c = [ NO ] 2 [ N 2 ] [ O 2 ] ; (c) Q c = [ SO 3 ] 2 [ SO 2 ] 2 [ O 2 ] ; (d) Q c = [SO 2 ]; (e) Q c = 1 [ P 4 ] [ O 2 ] 5 ; (f) Q c = [ Br ] 2 [ Br 2 ] ; (g) Q c = [ CO 2 ] [ CH 4 ] [ O 2 ] 2 ; (h) Q c = [H 2 O] 5

Got questions? Get instant answers now!

Write the mathematical expression for the reaction quotient, Q c , for each of the following reactions:

(a) N 2 ( g ) + 3 H 2 ( g ) 2 NH 3 ( g )

(b) 4 NH 3 ( g ) + 5 O 2 ( g ) 4 NO ( g ) + 6 H 2 O ( g )

(c) N 2 O 4 ( g ) 2 NO 2 ( g )

(d) CO 2 ( g ) + H 2 ( g ) CO ( g ) + H 2 O ( g )

(e) NH 4 Cl ( s ) NH 3 ( g ) + HCl ( g )

(f) 2 Pb ( NO 3 ) 2 ( s ) 2 PbO ( s ) + 4 NO 2 ( g ) + O 2 ( g )

(g) 2 H 2 ( g ) + O 2 ( g ) 2 H 2 O ( l )

(h) S 8 ( g ) 8 S ( g )

Got questions? Get instant answers now!

The initial concentrations or pressures of reactants and products are given for each of the following systems. Calculate the reaction quotient and determine the direction in which each system will proceed to reach equilibrium.

(a) 2 NH 3 ( g ) N 2 ( g ) + 3 H 2 ( g ) K c = 17 ; [NH 3 ] = 0.20 M , [N 2 ] = 1.00 M , [H 2 ] = 1.00 M

(b) 2 NH 3 ( g ) N 2 ( g ) + 3 H 2 ( g ) K P = 6.8 × 10 4 ; initial pressures: NH 3 = 3.0 atm, N 2 = 2.0 atm, H 2 = 1.0 atm

(c) 2 SO 3 ( g ) 2 SO 2 ( g ) + O 2 ( g ) K c = 0.230 ; [SO 3 ] = 0.00 M , [SO 2 ] = 1.00 M , [O 2 ] = 1.00 M

(d) 2 SO 3 ( g ) 2 SO 2 ( g ) + O 2 ( g ) K P = 16.5 ; initial pressures: SO 3 = 1.00 atm, SO 2 = 1.00 atm, O 2 = 1.00 atm

(e) 2 NO ( g ) + Cl 2 ( g ) 2 NOCl ( g ) K c = 4.6 × 10 4 ; [NO] = 1.00 M , [Cl 2 ] = 1.00 M , [NOCl] = 0 M

(f) N 2 ( g ) + O 2 ( g ) 2 NO ( g ) K P = 0.050 ; initial pressures: NO = 10.0 atm, N 2 = O 2 = 5 atm

(a) Q c 25 proceeds left; (b) Q P 0.22 proceeds right; (c) Q c undefined proceeds left; (d) Q P 1.00 proceeds right; (e) Q P 0 proceeds right; (f) Q c 4 proceeds left

Got questions? Get instant answers now!

The initial concentrations or pressures of reactants and products are given for each of the following systems. Calculate the reaction quotient and determine the direction in which each system will proceed to reach equilibrium.

(a) 2 NH 3 ( g ) N 2 ( g ) + 3 H 2 ( g ) K c = 17 ; [NH 3 ] = 0.50 M , [N 2 ] = 0.15 M , [H 2 ] = 0.12 M

(b) 2 NH 3 ( g ) N 2 ( g ) + 3 H 2 ( g ) K P = 6.8 × 10 4 ; initial pressures: NH 3 = 2.00 atm, N 2 = 10.00 atm, H 2 = 10.00 atm

(c) 2 SO 3 ( g ) 2 SO 2 ( g ) + O 2 ( g ) K c = 0.230 ; [SO 3 ] = 2.00 M , [SO 2 ] = 2.00 M , [O 2 ] = 2.00 M

(d) 2 SO 3 ( g ) 2 SO 2 ( g ) + O 2 ( g ) K P = 6.5 atm; initial pressures: SO 2 = 1.00 atm, O 2 = 1.130 atm, SO 3 = 0 atm

(e) 2 NO ( g ) + Cl 2 ( g ) 2 NOCl ( g ) K P = 2.5 × 10 3 ; initial pressures: NO = 1.00 atm, Cl 2 = 1.00 atm, NOCl = 0 atm

(f) N 2 ( g ) + O 2 ( g ) 2 NO ( g ) K c = 0.050 ; [N 2 ] = 0.100 M , [O 2 ] = 0.200 M , [NO] = 1.00 M

Got questions? Get instant answers now!

The following reaction has K P = 4.50 × 10 −5 at 720 K.
N 2 ( g ) + 3 H 2 ( g ) 2 NH 3 ( g )

If a reaction vessel is filled with each gas to the partial pressures listed, in which direction will it shift to reach equilibrium? P (NH 3 ) = 93 atm, P (N 2 ) = 48 atm, and P (H 2 ) = 52

The system will shift toward the reactants to reach equilibrium.

Got questions? Get instant answers now!

Determine if the following system is at equilibrium. If not, in which direction will the system need to shift to reach equilibrium?
SO 2 Cl 2 ( g ) SO 2 ( g ) + Cl 2 ( g )

[SO 2 Cl 2 ] = 0.12 M , [Cl 2 ] = 0.16 M and [SO 2 ] = 0.050 M . K c for the reaction is 0.078.

Got questions? Get instant answers now!

Which of the systems described in [link] give homogeneous equilibria? Which give heterogeneous equilibria?

(a) homogenous; (b) homogenous; (c) homogenous; (d) heterogeneous; (e) heterogeneous; (f) homogenous; (g) heterogeneous; (h) heterogeneous

Got questions? Get instant answers now!

Which of the systems described in [link] give homogeneous equilibria? Which give heterogeneous equilibria?

Got questions? Get instant answers now!

For which of the reactions in [link] does K c (calculated using concentrations) equal K P (calculated using pressures)?

This situation occurs in (a) and (b).

Got questions? Get instant answers now!

For which of the reactions in [link] does K c (calculated using concentrations) equal K P (calculated using pressures)?

Got questions? Get instant answers now!

Convert the values of K c to values of K P or the values of K P to values of K c .

(a) N 2 ( g ) + 3 H 2 ( g ) 2 NH 3 ( g ) K c = 0.50 at 400 °C

(b) H 2 + I 2 2 HI K c = 50.2 at 448 °C

(c) Na 2 SO 4 · 10 H 2 O ( s ) Na 2 SO 4 ( s ) + 10 H 2 O ( g ) K P = 4.08 × 10 −25 at 25 °C

(d) H 2 O ( l ) H 2 O ( g ) K P = 0.122 at 50 °C

(a) K P = 1.6 × 10 −4 ; (b) K P = 50.2; (c) K c = 5.31 × 10 −39 ; (d) K c = 4.60 × 10 −3

Got questions? Get instant answers now!

Convert the values of K c to values of K P or the values of K P to values of K c .

(a) Cl 2 ( g ) + Br 2 ( g ) 2 BrCl ( g ) K c = 4.7 × 10 −2 at 25 °C

(b) 2 SO 2 ( g ) + O 2 ( g ) 2 SO 3 ( g ) K P = 48.2 at 500 °C

(c) CaCl 2 · 6 H 2 O ( s ) CaCl 2 ( s ) + 6 H 2 O ( g ) K P = 5.09 × 10 −44 at 25 °C

(d) H 2 O ( l ) H 2 O ( g ) K P = 0.196 at 60 °C

Got questions? Get instant answers now!

What is the value of the equilibrium constant expression for the change H 2 O ( l ) H 2 O ( g ) at 30 °C?

K P = P H 2 O = 0.042 .

Got questions? Get instant answers now!

Write the expression of the reaction quotient for the ionization of HOCN in water.

Got questions? Get instant answers now!

Write the reaction quotient expression for the ionization of NH 3 in water.

Q c = [ NH 4 + ] [ OH ] [ HN 3 ]

Got questions? Get instant answers now!

What is the approximate value of the equilibrium constant K P for the change C 2 H 5 OC 2 H 5 ( l ) C 2 H 5 OC 2 H 5 ( g ) at 25 °C. (Vapor pressure was described in the previous chapter on liquids and solids; refer back to this chapter to find the relevant information needed to solve this problem.)

Got questions? Get instant answers now!
Practice Key Terms 7

Get Jobilize Job Search Mobile App in your pocket Now!

Get it on Google Play Download on the App Store Now




Source:  OpenStax, Chemistry. OpenStax CNX. May 20, 2015 Download for free at http://legacy.cnx.org/content/col11760/1.9
Google Play and the Google Play logo are trademarks of Google Inc.

Notification Switch

Would you like to follow the 'Chemistry' conversation and receive update notifications?

Ask