Question

use the references to access important values if needed for this question.
consider the following reaction where ( k_{c}=5.10\times10^{-6} ) at 548 k.
( nh_{4}cl(s)
ightleftharpoons nh_{3}(g)+hcl(g) )
a reaction mixture was found to contain 0.0536 moles of ( nh_{4}cl(s) ), 0.00154 moles of ( nh_{3}(g) ), and 0.00226 moles of ( hcl(g) ), in a 1.00 liter container.
is the reaction at equilibrium?
if not, what direction must it run in order to reach equilibrium?
the reaction quotient, ( q_{c} ), equals
the reaction
o must run in the forward direction to reach equilibrium.
o must run in the reverse direction to reach equilibrium.
o is at equilibrium.

Explanation:

Step1: Calculate the reaction quotient \(Q_c\)

For the reaction \(NH_4Cl(s)
ightleftharpoons NH_3(g)+HCl(g)\), the reaction quotient \(Q_c = [NH_3][HCl]\) (since \(NH_4Cl\) is a solid and its concentration is not included in the expression). Given the volume \(V = 1.00\space L\), the molar concentrations are equal to the number of moles. So, \([NH_3]=0.00154\space M\) and \([HCl]=0.00226\space M\). Then \(Q_c=(0.00154)\times(0.00226)\)

$$Q_c = 3.48\times10^{-6}$$

Step2: Compare \(Q_c\) with \(K_c\)

Given \(K_c = 5.10\times 10^{-6}\). Since \(Q_c=3.48\times 10^{-6}

Answer:

The reaction quotient \(Q_c\) equals \(3.48\times 10^{-6}\). The reaction must run in the forward direction to reach equilibrium.