Chapter 12, Problem 56QRT

(a)

Interpretation Introduction

Interpretation:

Whether the given cis-trans isomerization reaction of gaseous 2-butene is a product-favoured reaction or not has to be given.

Concept Introduction:

Equilibrium Constant & Direction of reaction:

Case 1: ${\text{K}}_{\text{c}}\gg \text{1}$:

Reaction is strongly product-favoured; equilibrium concentrations of products are much greater than equilibrium concentrations of reactants.

Case 2: ${\text{K}}_{\text{c}}\ll \text{1}$:

Reaction is strongly reactant-favoured; equilibrium concentrations of reactants are much greater than equilibrium concentrations of products.

Case 3: ${\text{K}}_{\text{c}}\cong \text{1}$:

Equilibrium mixture contains significant concentrations of reactants and products; calculations are needed to determine equilibrium concentrations.

(b)

Interpretation Introduction

Interpretation:

The amount (in moles) of trans iosmer produced when $\text{1 mol}$ of cis isomer is heated to $\text{580 K}$ in a $\text{1}\text{.00 L}$ flask has to be calculated.

Concept Introduction:

Equilibrium constant: At equilibrium the ratio of products to reactants (each raised to the power corresponding to its stoichiometric coefficient) has a constant value, K

For a general reaction,

  $\text{aA+bB}\rightleftarrows \text{cC+dD}$

  $\text{Equilibrium}\text{constant}\text{K}\text{=}\frac{{\left[\text{C}\right]}^{\text{c}}{\left[\text{D}\right]}^{\text{d}}}{{\left[\text{A}\right]}^{\text{a}}{\left[\text{B}\right]}^{\text{b}}}$

The concentration of solids and pure liquids do not change, so their concentration terms are not included in the equilibrium constant expression.

(c)

Interpretation Introduction

Interpretation:

The amount (in moles) of trans iosmer produced when $\text{1 mol}$ of cis isomer is heated to $\text{580 K}$ in a $\text{10}\text{.0 L}$ flask has to be calculated.

Concept Introduction:

Refer part (a).