1,1,1-trichloroethane + aqueous solution ?

如果 add chlorine 落 potassium iodide solution, 個reaction mixture 係咩?

The reaction mixture would become a solution of potassium chloride and iodine.

When chlorine (chlorine gas or chlorine water) is added to potassium iodide solution, displacement reaction occurs. The chlorine will be reduced to colourless chloride ion, while the iodide ion is oxidized to brown iodine solution.
Cl2(g/aq) + 2I-(aq) → 2Cl-(aq) + I2(aq)

=====
再add1,1,1-trichloroet hane 落個 reaction mixture, 會有咩野 observations ?

When 1,1,1-trichloroethane is added to the reaction mixture, the brown aqueous solution becomes paler in colour, and there is a purple layer of iodine in 1,1,1-trichloromethane at the bottom.

Iodine is more soluble in 1,1,1-trichloromethane than in water. Most of iodine is present in the 1,1,1-trichloromethane layer and the solution is purple in colour. Some iodine is left in the aqueous solution, and thus the colour of the aqueous solution changes to paler. Since 1,1,1-trichloromethane has a density greater than water, 1,1,1-trichloromethane layer would be at the bottom of the test tube.