Problem 64
Which of the following is insoluble in water? (a) \(\mathrm{CaF}_{2}\) (b) \(\mathrm{NaCl}\) (c) \(\mathrm{HgCl}_{2}\) (d) \(\mathrm{Ca}\left(\mathrm{NO}_{3}\right)_{2}\)
Problem 66
Initial setting of cement is mainly due to (a) hydration and hydrolysis (b) dehydration and gel formation
Problem 67
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) \(\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}, \mathrm{H}_{2} \mathrm{O}\)
Problem 70
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) \(\mathrm{Mg}+\mathrm{CO}_{2} \longrightarrow\)
Problem 71
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) \(\mathrm{CaSO}_{4} \cdot 2 \mathrm{H}_{2} \mathrm{O}\)
Problem 72
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
Problem 73
Aluminium reacts with concentrated \(\mathrm{HNO}_{3}\) and (a) liberates \(\mathrm{O}_{2}\) (b) liberates \(\mathrm{N}_{2}\) (c) becomes passive (d) forms AIN
Problem 74
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) \(\mathrm{Al}(\mathrm{OH})_{3}\)
Problem 75
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) \(\mathrm{NH}_{4} \mathrm{Cl}\)
Problem 76
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) \(\mathrm{Al}_{2} \mathrm{O}_{3} \cdot 2 \mathrm{H}_{2} \mathrm{O}\)
