SCl2(g) + 2 C2H4(g) <=> S(CH2CH2Cl)2(g)

Mustard gas, S(CH2CH2Cl)2 can be made at room temperature as shown:
SCl2(g) + 2 C2H4(g) <=> S(CH2CH2Cl)2(g)
In a particular experiment, 0.459 M of SCl2 and 0.919 M C2H4 were mixed. At equilibrium, [S(CH2CH2Cl)2(g)] was 0.141 M.
Calculate the value of Kc for the reaction.
Give your answer to 3 significant figures.

The answer is 1.09 but I dont know how to get it. can someone help me?

Prepare an ICE chart following the concentrations of each species during the reaction.

Molarity . . . . . .SCl2(g) + 2 C2H4(g) <=> S(CH2CH2Cl)2(g)
Initial . . . . . . . .0.459 . . . . 0.919 . . . . . .. . . . . .0
Change . . . . . . .-x . . . . . . .-2x . . . . . . . . . . . . x
Equilibrium . . .0.459-x . . .0.919-2x . . . . . . . . . .x

But we are told that at equilibrium, [S(CH2CH2Cl)2] = 0.141 M = x

[SCl2] = 0.459 - x = 0.459 - 0.141 = 0.318 M
[C2H4] = 0.919 - 2x = 0.919 - (2)(0.141) = 0.637 M

Kc = [S(CH2CH2Cl)2] / [SCl2][C2H4]^2 = (0.141) / (0.318)(0.637)^2 = 1.09

NH3 + NaOCl → NaOH + NH2Cl

NH2Cl + NaOCl → NaOH + NHCl2

NHCl2 + NaOCl → NaOH + NCl3

Additional reactions produce hydrazine, in a variation of the Olin Raschig process.

NH3 + NH2Cl + NaOH → N2H4 + NaCl + H2O

The hydrazine generated can further react with the monochloramine in an exothermic reaction:[6]

2 NH2Cl + N2H4 → 2 NH4Cl + N2