Answer: The partial pressure of [tex]Cl_2[/tex] is 1.86 atm
Explanation:
Equilibrium constant is defined as the ratio of concentration of products to the concentration of reactants each raised to the power their stoichiometric ratios. It is expressed as [tex]K_c[/tex]
The given balanced equilibrium reaction is,
               [tex]PCl_5(g)\rightleftharpoons PCl_3(g)+Cl_2(g)[/tex]
Pressure at eqm.    0.973 atm         0.548atm    x atm
The expression for equilibrium constant for this reaction will be,
[tex]K_c=\frac{(p_{PCl_3}\times (p_{Cl_2})}{(p_{PCl_5})}[/tex]
Now put all the given values in this expression, we get :
[tex]1.05=\frac{(0.548)\times (x)}{(0.973)}[/tex]
By solving the term 'x', we get :
x = 1.86 atm
Thus, the partial pressure of [tex]Cl_2[/tex] is 1.86 atm