question_answer 124)

    An element X which is a yellow solid at room temperature shows catenation arid allotropy. X forms two oxides which are also formed during the thermal, decomposition of ferrous sulphate crystals and are the major air pollutant (a) Identify the element X. (b) Write the electronic configuration of X. (c) Write the balanced chemical equation for the thermal decomposition of ferrous sulphate crystals? (d) What would be the nature (acidic/basic) of oxides formed? (e) Locate the position of the element in the modern periodic table.

Answer:

                  (a) Element X which is a yellow solid at room temperature, shows catenation and allotropy is sulphur (S). It forms two oxides SO2 and SO3 which are also formed during thermal decomposition of ferrous sulphate crystals and are the major air pollutants. (b) Atomic number of S = 16                 Its electron configuration is  (c) Both SO2 and SO3 are major air pollutants. (d) Since, sulphur is a non-metal, therefore, both SO2 and SO3 are acidic oxides.(non-metals form acidic oxides). They dissolve in water to form the corresponding acids. (e) Since, sulphur contains six valence electrons; therefore, it lies in group 6+10=16. Further, since atomic number of sulphur (S) is16, electronic configuration is. So, it lies in 3rdperiod.