Answer
See the answer below.
Work Step by Step
a) Initial concentration: $6.70\ g\div 134.97\ g/mol\div 10.0\ L=0.005\ M$, reacted x
$K_c=[SO_2][Cl_2]/[SO_2Cl_2]$
$0.045=x^2/(0.005-x)$
$x=0.00454$
$[SO_2]=[Cl_2]=0.00454\ M, [SO_2Cl_2]=0.00046\ M$
$f_R=0.00454/0.005\times100\%=90.8\%$
b) Initial concentration of Cl2: $0.10\ atm/RT=0.0019\ M$
$K_c=[SO_2][Cl_2]/[SO_2Cl_2]$
$0.045=x(0.0019+x)/(0.005-x)$
$x=0.00439$
$[SO_2]=0.00454\ M, [Cl_2]=0.00627\ M, [SO_2Cl_2]=0.00061\ M$
$f_R=0.00439/0.005\times100\%=87.8\%$
c) As expected, the addition of a product shifts the equilibrium to the formation of reactants, decreasing its conversion.
