Which of the following statements are not correct? Rectify them. (a) sodium when heated in excess of air forms sodium oxide. (b) Solvay ammonia process is employed for the manufacture of both Na_(2)CO_(3) and K_(2)CO_(3). (c ) Rock salt is chemically NaCI. (d) Water glass is sodium silicate. (e) NaHCO_(3) is less soluble in water then KHCO_(3). (f) Potassium is used in photoelectric cells. (g) The solution of Na_(2)CO_(3) in water is basic due to cationic hydrolysis. Microcosmic salt has formula Na(NH_(4)) HPO_(4).4H_(2)O (i) Glaubar's salt is Na_(2)SO_(4).5H_(2)O. (j) Sodium carbonate upon heating forms CO_(2).

Which of the following statements are not correct? Rectify them. (a)

1.	Which of the following statements are not correct? Rectify them. (a) sodium when heated in excess of air forms sodium oxide. (b) Solvay ammonia process is employed for the manufacture of both Na_(2)CO_(3) and K_(2)CO_(3). (c ) Rock salt is chemically NaCI. (d) Water glass is sodium silicate. (e) NaHCO_(3) is less soluble in water then KHCO_(3). (f) Potassium is used in photoelectric cells. (g) The solution of Na_(2)CO_(3) in water is basic due to cationic hydrolysis. Microcosmic salt has formula Na(NH_(4)) HPO_(4).4H_(2)O (i) Glaubar's salt is Na_(2)SO_(4).5H_(2)O. (j) Sodium carbonate upon heating forms CO_(2).
Answer» Solution :(a) Sodium upon heating in excess of air forms sodium peroxide. `2Na + O+_(2) to Na_(2)O_(2)` (b) Solvay Ammonia process is employed for the manufacture of only `Na_(2)CO_(3)` because in case of `K_(2)CO_(3)`, the hydrogen carbonate `(KHCO_(3))` expected to be initially formed in the reaction is HIGHLY soluble and can not be precipitated. ltbgt (g) The solution of `Na_(2)CO_(3)` in WATER is basic due to anionic hydrolysis and not cationic hydrolysis. Only `CO_(3)^(2-)` IONS (anions) have reacted with `H^(+)` ions while `Na^(+)` ions do not COMBINE with `OH^(-)` ions. `Na_(2)CO_(3) to 2Na^(+) + CO_(3)^(2-)` `2HOH hArr 2H^(+) + 2OH^(-)` `2H^(+) + CO_(3)^(2-) hArr H_(2)CO_(3)` (i) Glauber's salt is `Na_(2)SO_(4).10H_(2)O` Sodium carbonate does not DECOMPOSE upon heating.