Question #19cd0
1 Answer
Explanation:
Start with the balanced chemical equation for this equilibrium reaction
#color(red)(2)"CH"_2"Cl"_text(2(g]) rightleftharpoons "CH"_text(4(g]) + "CCl"_text(4(g])#
By definition, the equilibrium constant,
Mathematically,
#K_c = ( ["CH"_4] * ["CCl"_4])/(["CH"_2"Cl"_2]^color(red)(2))#
Keep in mind, these are all equilibrium concentrations used in the expression for
Now, you know that this reaction has a
Moreover, you know that at equilibrium, the reaction vessel contains
#["CH"_2"Cl"_2] = 2.36 * 10^(-2)"M"#
and
#["CH"_4] = 2.42 * 10^(-2)"M"#
Even without doing any calculations, you could predict that the concentration of carbon tetrachloride,
That happens because the value of
Since the equilibrium concentrations of the reactant and of one of the products are approximately equal, the magnitude of
You can determine the equilibrium concentration for
#K_c = ( ["CH"_4] * ["CCl"_4])/(["CH"_2"Cl"_2]^color(red)(2)) implies ["CCl"_4] = K_c * (["CH"_2"Cl"_2]^color(red)(2))/(["CH"_4])#
Plug in your values to get
#["CCl"_4] = 10.5 * ( (2.36 * 10^(-2))^color(red)(2)"M"^color(red)(cancel(color(black)(2))))/( 2.42 * 10^(-2)color(red)(cancel(color(black)("M")))) = 24.166 * 10^(-2)"M"#
Rounded to three sig figs, the answer will be
#["CCl"_4] = color(green)(2.42 * 10^(-1)"M")#
Indeed, the initial predict appears to be correct, you do have about