Chemistry - Complete s-block Question with Solution | TestHub
Consider the statements:
(a) is amphoteric.
(b) cannot be isolated in the solid state.
(c) is paramagnetic, while is diamagnetic.
(d) On heating, gives and .
(e) Anhydrous calcium chloride is used as a drying agent for ammonia gas.
(f) Sodium hydroxide is recovered and recycled in the ammonia-recovery step of the Solvay process.
(g) In the Downs process, electrolysis of molten sodium chloride liberates sodium at the cathode.
(h) dissolves in excess sodium hydroxide to form .
If X is the number of correct statements and Y is the number of incorrect statements, find rounded to two decimal places.
Answer:
Solution:
(a) True: beryllium oxide reacts with acids and alkalis.
(b) True: lithium hydrogencarbonate is stable only in solution.
(c) True: superoxide has one unpaired electron, while peroxide has none.
(d) True: sodium nitrate decomposes to sodium nitrite and oxygen on heating.
(e) False: calcium chloride absorbs ammonia, so it cannot be used to dry that gas.
(f) False: ammonia, rather than sodium hydroxide, is recovered using calcium hydroxide.
(g) True: sodium ions are reduced to sodium at the cathode.
(h) True: amphoteric beryllium hydroxide dissolves to form the tetrahydroxidoberyllate ion.
Thus , and .
