Question #d2eaf
1 Answer
I got
What you've effectively asked for is, "what is the percent of
Let
The ICE table becomes:
#"H"_2(g) " "+" " "I"_2(g) rightleftharpoons 2"HI"(g)#
#"I"" "n" "" "" "" "" "n" "" "" "0#
#"C"" "-x" "" "" "-x" "" "+2x#
#"E"" "n-x" "" "n-x" "" "2x#
Remember that the amount of reactant lost or product gained is weighted by the stoichiometric coefficient of that substance. It also shows up in the exponent.
So, the equilibrium constant is:
#K_c = 70.0 = (["HI"]^2)/(["H"_2]["I"_2])#
#= (2x)^2/((n-x)(n-x))#
That means this is easily solved without using the quadratic formula to find
#sqrt(70.0) = (2x)/(n-x)#
#nsqrt(70.0) - sqrt(70.0)x = 2x#
#(2 + sqrt(70.0))x = nsqrt(70.0)#
#=> x = sqrt(70.0)/(2 + sqrt(70.0))n#
#~~ 0.807n#
The amount of
#color(blue)(%"I"_2) = (x)/(n) = (0.807n)/(n) ~~ color(blue)(80.7%)#