Question

The reaction 3A(g)B(s)2C(aq)D(ag) occurs at 25°C in a flask, which has 3.01 L available for gas. After the reaction attains equilibrium, the amounts (mol) or concentrations (M) of substances are as follows: 6.13 mol A, 2.37 M C 1.90 mol B, 3.10 M D What is the equilibrium constant Ke for this reaction at 25°C?

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Answer 1

1,) since active concentration of solid remain constant throughout reaction, it is not included in equilibrium constant expression.Kc is written in terms of molar concentration of active species.

Concentration of A = [ A ] = 6.13 mol / 3.01 Lt = 2.0365 M

K_{​​​​​C} = [ C]² [ D ] / [ A ]³ = ( 2.37 M )² ( 3.10M ) / ( 2.0365 M)³

= 2.06

2) when 1 mol of N2O3 reacts it form 1 mol of NO2 and 1 mol of NO according to reaction stoichiometry.

Since 0.55 mol of NO2 formed it means equal number of moles of N2O3 reacted.

Mol of N2O3 ( g ) = 8.49 - 0.55 = 7.94 mol

Mol of NO2 ( g ) = 0.55 mol

Mol of NO ( g ) = 0.55 mol