For each reaction, identify the element that gets reduced and the element that gets oxidized. 2AgCl+Zn⟶2Ag+ZnCl2 Identify the element that gets reduced. chlorine zinc silver Identify the element that gets oxidized. chlorine silver zinc 4NH3+3O2⟶2N2+6H2O Identify the element that gets reduced. hydrogen oxygen nitrogen Identify the element that gets oxidized. nitrogen oxygen hydrogen Fe2O3+2Al⟶Al2O3+2Fe Identify the element that gets reduced. oxygen aluminum iron Identify the element that gets oxidized. aluminum oxygen iron

answer: - first one is the correct answer. .

explanations: - potassium sulfide is and cobalt(ii) chloride is .

charge on k is +1, charge on s is -2, charge on co is +2 and charge on cl is -1.

in a double replacement reaction the ion exchange takes place. in general the reaction looks like:

if one of the product is insoluble as per solubility rules then a precipitate of it is formed.

when we mix the aqueous solutions of potassium sulfide and cobalt(ii) chloride then chloride ion goes with potassium ion and sulfide ion goes with cobalt ion and the balanced equation is written as:

k and cl has equal charges, similarly co and s has equal charges and hence no subscripts are used for the product side.

as per the solubility rules, cos is insoluble and so it's precipitate is formed.

looking at the given choices, first choice is correct.