Chapter 17

\(\mathrm{Mg}\) is an important component of which biomolecule occurring extensively in living world? (a) cholorophyll (b) haemoglobin (c) \(\mathrm{ATP}\) (d) florigen

Plaster of paris is used (a) in dentistry and surgery (b) as a plaster for walls (c) as a drying agent (d) in metallurgical process

The reaction of slaked lime with \(\mathrm{Cl}_{2}\) gas gives (a) a mixture of \(\mathrm{Ca}(\mathrm{OCl})_{2}, \mathrm{Ca}(\mathrm{OH})_{2}, \mathrm{CaCl}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\) (b) quick lime (c) Baryta water (d) only \(\mathrm{Ca}(\mathrm{OCl})_{2}\)

The compound insoluble in acetic acid is (a) calcium oxide (b) calcium carbonate (c) calcium oxalate (d) calcium hydroxide

The hydration energy or \(\mathrm{Mg}^{2+}\) ions is higher than that of (a) \(\mathrm{Al}^{3+}\) (b) \(\mathrm{Be}^{2+}\) (c) \(\mathrm{Na}^{+}\) (d) none of these

On heating quick lime with coke in an electric furnace, we get (a) \(\mathrm{CaC}_{2}\) (b) \(\mathrm{CaCO}_{3}\) (c) \(\mathrm{CaO}\) (d) \(\mathrm{Ca}\) and \(\mathrm{CO}_{2}\)

Limestone is not used in which of the following manufacturing processes? (a) Portland cement (b) phosphorus from phosphorite (c) iron form haematite (d) Solvay process of sodium carbonate

Solution of \(\mathrm{MgCl}_{2}\) in water has \(\mathrm{pH}\) value (a) 7 (b) \(\geq 7\) (c) \(<7\) (d) \(14.2\)

A solution of \(\mathrm{Ca}\) in liquid ammonia when evaporated to dryness gives as residue of (a) \(\left[\mathrm{Ca}\left(\mathrm{NH}_{3}\right) \mathrm{x}\right]^{2+}\) (b) \(\mathrm{Ca}\left(\mathrm{NH}_{3}\right)_{6}\) (c) pure Ca (d) \(\left[\mathrm{Ca}\left(\mathrm{NH}_{3}\right)_{6}\right]^{2+}\)

Magnesium can be obtained by (a) reducing magnesium salt solution with \(\mathrm{Fe}\) (b) electrolysis of fused magnesium salt (c) electrolysis of \(\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2}\) solution (d) reducing \(\mathrm{MgO}\) with coke

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

Carnalite on electrolysis gives (a) \(\mathrm{Na}\) and \(\mathrm{CO}_{2}\) (b) \(\mathrm{Mg}\) and \(\mathrm{Cl}_{2}\) (c) \(\mathrm{Al}\) and \(\mathrm{Cl}_{2}\) (d) \(\mathrm{Ca}\) and \(\mathrm{Cl}_{2}\)

Initial setting of cement is mainly due to (a) hydration and hydrolysis (b) dehydration and gel formation (c) dehydration and dehydrolysis (d) hydration 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) \(\mathrm{Mg}(\mathrm{OH})_{2}^{2}, \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{MgCO}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{CO}_{2}\) (d) \(\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}, \mathrm{H}_{2} \mathrm{O}^{2}\)

Silica reacts with \(\mathrm{Mg}\) to form a magnesium compound X. X reacts with dilute HCl and forms Y. Y is (a) \(\mathrm{MgCl}_{2}\) (b) \(\mathrm{MgO}\) (c) \(\mathrm{SiCl}_{4}\) (d) \(\mathrm{MgSiO}\)

One of the elements present in carnalite shows flame colouration. The colour of the flame is (a) green (b) lilac (c) yellow (d) orange

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) \(\mathrm{Mg}+\mathrm{CO}_{2} \longrightarrow\)

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) \(\mathrm{NH}_{4}^{3} \mathrm{Cl}\)

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) \(\mathrm{Al}_{2} \mathrm{O}_{3} \cdot 2 \mathrm{H}_{2} \mathrm{O}\)

What is formed when aluminium trioxide reacts with sodium? (a) \(\mathrm{NaO}\) (b) \(\mathrm{NaO}_{2}\) (c) \(\mathrm{Na}_{2} \mathrm{O}\) (d) \(\mathrm{Na}_{2} \mathrm{O}_{2}\)

The alum used for purifying water is (a) potash alum (b) chrome alum (c) ferric alum (d) ammonium alum

What is formed when nitrogen reacts with alumina in presence of carbon at \(2100 \mathrm{~K} ?\) (a) \(\mathrm{AlN}_{2}\) (b) AIN (c) \(\mathrm{AlN}_{3}\) (d) \(\mathrm{AlC}_{2}\)

Which of the following alloy is used for making magnets for hearing aids? (a) invar (b) german silver (c) monel metal (d) alnico

Emery consists of impure (a) iron (b) corundum (c) carborundum (d) graphite

The molecular formula of potash alum is (a) \(\mathrm{K}_{2} \mathrm{Al}_{2} \mathrm{~S}_{2} \mathrm{H}_{48} \mathrm{O}_{39}\) (b) \(\mathrm{KAl}_{2} \mathrm{~S}_{2} \mathrm{H}_{43} \mathrm{O}_{40}\) (c) \(\mathrm{K}_{2} \mathrm{AlS}_{2} \mathrm{H}_{48} \mathrm{O}_{40}\) (d) \(\mathrm{K}_{2} \mathrm{Al}_{2} \mathrm{~S}_{2} \mathrm{H}_{48} \mathrm{O}_{40}\)

Which of the following is not correct? (a) Al reacts with \(\mathrm{NaOH}\) and liberates \(\mathrm{H}_{2}\) (b) \(\mathrm{AlCl}_{3}\) is a Lewis acid (c) \(\mathrm{Al}\) is used in the manufacture of electrical cables (d) \(\mathrm{NaOH}\) is used during Halls process of purification of bauxite

Which of the following is known as pseudo alum? (a) \(\mathrm{K}_{2} \mathrm{SO}_{4} \cdot \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} \cdot 24 \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{KCr}\left(\mathrm{SO}_{4}\right)_{2} \cdot 12 \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{KMn}\left(\mathrm{SO}_{4}\right)_{2} \cdot 12 \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{NH}_{4} \mathrm{Fe}\left(\mathrm{SO}_{4}\right)_{2} \cdot 12 \mathrm{H}_{2} \mathrm{O}\)

Sodium hydroxide being hygroscopic absorbs moisture when exposed to the atmosphere. A student placed a pellet of \(\mathrm{NaOH}\) on a watch glass. A few days later, he noticed that the pellet was covered with a white solid. Identify this white solid? (a) Na metal (b) \(\mathrm{Na}_{2} \mathrm{SO}_{3}\) (c) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (d) \(\mathrm{Na}_{2} \mathrm{~S}\)

In the reaction: \(\mathrm{K}_{4}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]+\mathrm{K}_{2} \mathrm{CO}_{3} \longrightarrow\) the product formed is (a) \(\mathrm{FeCO}_{3}\) (b) \(\mathrm{KCN}\) (c) \(\mathrm{KFeCO}_{3}\) (d) \(\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{4}\right]\)

In electrolysis of \(\mathrm{NaCl}\) when \(\mathrm{Pt}\) electrode is used, then \(\mathrm{H}_{2}\) is liberated at cathode while with Hg cathode it forms sodium amalgam. The reason for this is (a) more voltage is required to reduce \(\mathrm{H}^{+}\)at \(\mathrm{Hg}\) than at \(\mathrm{Pt}\) (b) concentration of \(\mathrm{H}^{+}\)ions is larger when \(\mathrm{Pt}\) electrode is taken. (c) Na is dissolved in Hg while it does not dissolve in Pt (d) \(\mathrm{Hg}\) is more inert than \(\mathrm{Pt}\)

A certain metal \(\mathrm{M}\) is used to prepare an antacid, which is used as a medicine for acidity. This metal accidently catches fire, which can not be extinguished by using \(\mathrm{CO}_{2}\) based extinguishers. The metal \(\mathrm{M}\) is (a) \(\mathrm{Mg}\) (b) \(\mathrm{Ba}\) (c) \(\mathrm{Be}\) (d) \(\mathrm{C}\)

In the detection of sulphur, sodium nitroprusside solution is added to the Lassaigne's test solution, a purple coloured is obtained. It is due to (a) \(\mathrm{Na}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{5} \mathrm{NOSNa}\right]\) (b) \(\mathrm{Na}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{6}\right]\) (c) \(\mathrm{Fe}(\mathrm{CNS})_{3}\) (d) \(\mathrm{Na}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{5} \mathrm{NS}\right]\)

In the reaction: \(\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} \cdot 18 \mathrm{H}_{2} \mathrm{O} \frac{\mathrm{Heat}}{-18 \mathrm{H}_{2} \mathrm{O}}-\mathrm{A} \stackrel{800^{\circ} \mathrm{C}}{\longrightarrow} \mathrm{B}+\mathrm{C}\) The product \(\mathrm{A}, \mathrm{B}\) and \(\mathrm{C}\) are respetively (a) \(\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}, \mathrm{Al}_{2} \mathrm{O}_{3}, \mathrm{SO}_{3}\) (b) \(\mathrm{Al}_{2} \mathrm{O}_{3}, \mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}, \mathrm{SO}_{3}\) (c) \(\mathrm{Al}_{2} \mathrm{SO}_{4}, \mathrm{Al}_{2} \mathrm{O}_{3}, \mathrm{SO}_{3}\) (d) \(\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3}, \mathrm{Al}_{2} \mathrm{O}_{3}, \mathrm{SO}_{2}\)

Gas 'A' is bubbled through slaked lime when a white precipitate is formed. On prolonged bubbling the precipitate dissolved. On heating the resultant solution, the white precipitate reappeared with solution of gas 'B'. The gases 'A' and 'B' respectively are (a) \(\mathrm{CO}\) and \(\mathrm{CO}_{2}\) (b) \(\mathrm{CO}_{2}\) and \(\mathrm{CO}_{2}\) (c) \(\mathrm{CO}\) and \(\mathrm{CO}\) (d) \(\mathrm{CO}_{2}\) and \(\mathrm{CO}\)

Which of the following set of raw materials are used in the manufacture of \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) by Solvay process? (a) \(\mathrm{CaCl}_{2}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) (b) \(\mathrm{NaOH}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) (c) \(\mathrm{NaCl}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\) (d) \(\mathrm{Ca}(\mathrm{OH})_{2}, \mathrm{NH}_{3}, \mathrm{CO}_{2}\)

A burning strip of magnesium is introduced into a jar containing a gas. After sometimes the walls of the container is coated with carbon. The gas in the container is (a) \(\mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{CO}_{2}\) (c) \(\mathrm{O}_{2}\) (d) \(\mathrm{N}_{2}\)

Halides of alkaline earth metals form hydrates such as \(\mathrm{MgCl}_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}, \quad \mathrm{CaCl}_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}, \quad \mathrm{BaCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}\) and \(\mathrm{SrCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O} .\) This shows that halides of group 2 elements (a) can absorb moisture form air (b) act as dehydrating agents (c) are hydroscopic in nature (d) all of the above

A deliquescent white crystalline hydroxide \(X\) reacts with a nitrate \(\mathrm{Y}\) to form another hydroxide which decomposes to give a insoluble brown layer of its oxide. \(X\) is a powerful cautery and breaks down then proteins of skin flesh to a pasty mass. \(\mathrm{X}\) and \(\mathrm{Y}\) are (a) \(\mathrm{NaOH}, \mathrm{Zn}\left(\mathrm{NO}_{3}\right)_{2}\) (b) \(\mathrm{NaOH}, \mathrm{AgNO}_{3}\) (c) \(\mathrm{Ca}(\mathrm{OH})_{2} \cdot \mathrm{HgNO}_{3}\) (d) \(\mathrm{NaOH}, \mathrm{Al}\left(\mathrm{NO}_{3}\right)_{3}\)

Solution of sodium metal in liquid ammonia is strongly reducing due to the presence in solution of the following (a) solvated electrons (b) sodium atoms (c) sodium hydride (d) sodium amide

Consider the following reactions: \(\mathrm{X}+\mathrm{HCl} \frac{\text { Anhyd } \mathrm{AlCl}_{3}}{\text { (addition) }} \mathrm{C}_{2} \mathrm{H}_{5} \mathrm{Cl}\) \(\frac{\text { Anhyd. } \mathrm{ZnCl}_{2} / \mathrm{HCl}_{3}}{\text { (substitution) }}\) \(\mathrm{Y}\) can be converted to \(\mathrm{X}\) on heating with \(\ldots \ldots\) at..........temperature. (a) \(\mathrm{Cu}, 300^{\circ} \mathrm{C}\) (b) \(\mathrm{Al}_{2} \mathrm{O}_{3}, 350^{\circ} \mathrm{C}\) (c) \(\mathrm{NaOH} / \mathrm{I}_{2}, 60^{\circ} \mathrm{C}\) (d) \(\mathrm{Ca}(\mathrm{OH})_{2}^{2}+\mathrm{CaOCl}_{2}, 60^{\circ} \mathrm{C}\)

A metal (A) heating in nitrogen gas gives (B). (B) on treatment with \(\mathrm{H}_{2} \mathrm{O}\) gives a colourless gas which on passing through \(\mathrm{CuSO}_{4}\) solution turns it deep blue. Here (B) is (a) \(\mathrm{NH}_{z}\) (b) \(\mathrm{MgO}\) (c) \(\mathrm{Mg}\left(\mathrm{NO}_{3}\right)_{2}\) (d) \(\mathrm{Mg}_{3} \mathrm{~N}_{2}\)

Which of the following is correct? (a) sodium reduces \(\mathrm{CO}_{2}\) to carbon (b) in the Castner's process of sodium extraction, \(\mathrm{NaCl}\) is used as an electrolyte (c) magnalium is an alloy of \(\mathrm{Mg}\) and \(\mathrm{Zn}\) (d) \(\mathrm{Mg}\) reacts with cold water and liberate hydrogen gas

\(\mathrm{MgSO}_{4}\) on reaction with \(\mathrm{NH}_{4} \mathrm{OH}\) and \(\mathrm{Na}_{2} \mathrm{HPO}_{4}\) forms a white crystalline precipitate. What is its formula? (a) \(\mathrm{Mg}\left(\mathrm{NH}_{4}\right) \mathrm{PO}_{4}\) (b) \(\mathrm{Mg}_{3}\left(\mathrm{PO}_{4}\right)_{2}\) (c) \(\mathrm{MgCl}_{2} \cdot \mathrm{MgSO}_{4}\) (d) \(\mathrm{MgSO}_{4}\)

A sodium salt on treatment with \(\mathrm{MgCl}_{2}\) gives white precipitate only on heating. The anion of the sodium salt is (a) \(\mathrm{HCO}_{3}^{-}\) (b) \(\mathrm{CO}_{3}^{2-}\) (c) \(\mathrm{NO}_{3}^{-}\) (d) \(\mathrm{SO}_{4}^{2-}\)

The metallic lusture exhibited by sodium is explained by (a) diffusion of sodium ions (b) oscillation of loose electrons (c) excitation of free electrons (d) existence of body centred cubic lattice.

Which of the following changes occur when an excess of \(\mathrm{CO}_{2}\) gas is passed into a clear solution of lime water? (a) a white precipitate containing both \(\mathrm{CaCO}_{3}\) and \(\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}\) is formed (b) initially a white precipitate of \(\mathrm{CaCO}_{3}\) is formed which changes into soluble \(\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}\) on passing \(\mathrm{CO}_{2}\) gas (c) a white precipitate of \(\mathrm{Ca}\left(\mathrm{HCO}_{3}\right)_{2}\) is formed (d) a white precipitate of \(\mathrm{CaCO}_{3}\) is formed

Sodium sulphate is soluble in water whereas barium sulphate is sparingly soluble because (a) the hydration energy of sodium sulphate is more than its lattice energy (b) the lattice energy of barium sulphate is less than its hydration energy (c) the lattice energy has no role to play in solubility (d) the hydration energy of sodium sulphate is less than its lattice energy