91Ó°ÊÓ

Which of the following is insoluble in water? (a) \(\mathrm{CaF}_{2}\) (b) \(\mathrm{NaCl}\) (c) \(\mathrm{HgCl}_{2}\) (d) \(\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}\)

Initial setting of cement is mainly due to (a) hydration and hydrolysis (b) dehydration and gel formation

What are the products formed when an aqueous solution of magnesium bicarbonate is boiled? (a) \(\mathrm{Mg}, \mathrm{CO}_{2}, \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{Mg}(\mathrm{OH})_{2}, \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{MgCO}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{CO}_{2}\) (d) \(\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}, \mathrm{H}_{2} \mathrm{O}\)

In which of the following reactions \(\mathrm{MgO}\) is not formed? (a) \(\mathrm{Mg}+\mathrm{B}_{2} \mathrm{O}_{3} \longrightarrow\) (b) \(\mathrm{Mg}+\mathrm{NO}_{2} \longrightarrow\) (c) \(\mathrm{Mg}+\mathrm{dil} . \mathrm{HNO}_{3} \longrightarrow\) (d) \(\mathrm{Mg}+\mathrm{CO}_{2} \longrightarrow\)

Which one of the following is dead burnt plaster? (a) anhydrous \(\mathrm{CaSO}_{4}\) (b) \(\mathrm{CaSO}_{3}\) (c) \(\left(\mathrm{CaSO}_{4}\right)_{2} \cdot \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{CaSO}_{4} \cdot 2 \mathrm{H}_{2} \mathrm{O}\)

Aluminium vessles should not be washed with materials containing washing soda because (a) washing soda reacts with aluminum to form insoluble aluminium oxide (b) washing soda reacts with aluminium to form soluble aluminate. (c) washing soda is expensive (d) washing soda is easily decomposed

Aluminium reacts with concentrated \(\mathrm{HNO}_{3}\) and (a) liberates \(\mathrm{O}_{2}\) (b) liberates \(\mathrm{N}_{2}\) (c) becomes passive (d) forms AIN

Which of the following is obtained when \(\mathrm{NH}_{4} \mathrm{OH}\) is added to \(\mathrm{AlCl}_{3}\) solution? (a) \(\mathrm{NH}_{3}\) (b) \(\mathrm{NH}_{4} \mathrm{Cl}\) (c) \(\mathrm{NH}_{4}\) (d) \(\mathrm{Al}(\mathrm{OH})_{3}\)

Which of the following is formed when aluminium nitride is heated with \(\mathrm{HCl}\) at \(900^{\circ} \mathrm{C}\) ? (a) \(\mathrm{AlCl}_{3}\) (b) \(\mathrm{AlH}_{3}\) (c) \(\mathrm{Al}_{2} \mathrm{Cl}_{3}\) (d) \(\mathrm{NH}_{4} \mathrm{Cl}\)

The composition of diaspore is (a) \(\mathrm{Al}_{2} \mathrm{O}_{3} \cdot 3 \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{Al}_{2} \mathrm{O}_{3} \cdot \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{Al}_{2} \mathrm{O}_{3}\) (d) \(\mathrm{Al}_{2} \mathrm{O}_{3} \cdot 2 \mathrm{H}_{2} \mathrm{O}\)