Elements X,Y and Z belong to the same period in the Periodic Table. The properties of oxides of elements X, Y and Z are given in the following table.
Oxide of X - soluble in HCl and aq. NaOH
Oxide of Y - Decolourises acidified KMnO4 solution
Oxide of Z - Whe heated with NH4Cl releases a pungent gas which turn moist red litmus paper blue
List the elements in order of increasing proton number.
I think X is aluminium, Y is sulphur, and Z something alkaline. Not sure. Should be Na2O or MgO. so is the sequence Z, X, Y?
I believe the question never ask you to identify the elements. So presuming the elements you have listed are correct, the it should be Z, X, Y. (Also assuming that it's period 3 according to your answers)
Oxide of X is clearly amphoteric.
Oxide of Y can expand its octet because it can be oxidized. Group I and II cannot expand their octet. (P or S)
Oxide of Z is a basic oxide, a simple acid base reaction with ammonium chloride where ammonium acts as the conjugate acid. (Na or Mg)
Alright. But I think there's no way you can identify the elements because of insufficient data. Correct me if I'm wrong.