Chapter 17

Magnesium can be obtained by (a) reducing magnesium salt solution with 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

The compound formed when gypsum is dissolved in aqueous ammonium sulphate solution is (a) \(\mathrm{CaSO}_{4} \cdot \mathrm{NH}_{3} \mathrm{Cl} \cdot \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{CaSO}_{4} \cdot\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4} \cdot \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{CaCl}_{2} . \mathrm{NH}_{4} \mathrm{Cl} .2 \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{CaCl}_{2} \cdot\left(\mathrm{NH}_{4}\right)_{2} \mathrm{SO}_{4} \cdot \mathrm{H}_{2} \mathrm{O}\)

Fluorosis disease is caused due to the reaction of \(\ldots \ldots\).. with excess of fluoride in the body. (a) \(\mathrm{Mg}\) (b) \(\mathrm{Fe}\) (c) \(\mathrm{K}\) (d) \(\mathrm{Ca}\)

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 (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) \(\mathrm{Mg}(\mathrm{OH})_{2}, \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{MgCO}_{3}, \mathrm{H}_{2} \mathrm{O}, \mathrm{CO}_{2}\) (d) \(\mathrm{Mg}\left(\mathrm{HCO}_{3}\right)_{2}, \mathrm{H}_{2} \mathrm{O}\)

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

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) \(\mathrm{CaSO}_{4} .2 \mathrm{H}_{2} \mathrm{O}\)

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

The reducing agent in thermite process is (a) \(\mathrm{Mg}\) (b) \(\mathrm{BaO}_{2}\) (c) \(\mathrm{Al}\) (d) \(\mathrm{MnO}_{2}\)

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

The molecular formula of potash alum is (a) \(\mathrm{K}_{2} \mathrm{Al}_{2} \mathrm{~S}_{2} \mathrm{H}_{43} \mathrm{O}_{39}\) (b) \(\mathrm{KAl}_{2} \mathrm{~S}_{2} \mathrm{H}_{48} \mathrm{O}_{40}\) (c) \(\mathrm{K}_{2} \mathrm{AlS}_{2} \mathrm{H}_{43} \mathrm{O}_{40}\) (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) 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) \(\mathrm{KMn}\left(\mathrm{SO}_{4}\right)_{2} .12 \mathrm{H}_{2} \mathrm{O}\) (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) \(\mathrm{K}_{3}\left[\mathrm{Fe}(\mathrm{CN})_{4}\right]\)

Which one of the following reactions is not associated with the Solvay process of manufacture of sodium carbonate? (a) \(\mathrm{NaCl}+\mathrm{NH}_{4} \mathrm{CO}_{3} \longrightarrow \mathrm{NaHCO}_{3}+\mathrm{NH}_{4} \mathrm{Cl}\) (b) \(2 \mathrm{NaOH}+\mathrm{CO}_{2} \longrightarrow \mathrm{Na}_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{O}\) (c) \(2 \mathrm{NaHCO}_{3} \longrightarrow \mathrm{Na}_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{O}+\mathrm{CO}_{2}\) (d) \(\mathrm{NH}_{3}+\mathrm{H}_{2} \mathrm{CO}_{3} \longrightarrow \mathrm{NH}_{4} \mathrm{HCO}_{3}\)

In electrolysis of \(\mathrm{NaCl}\) when \(\mathrm{Pt}\) electrode is used, then \(\mathrm{H}_{2}\) is liberated at cathode while with \(\mathrm{Hg}\) 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) \(\mathrm{Na}\) is dissolved in \(\mathrm{Hg}\) while it does not dissolve in \(\mathrm{Pt}\) (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: \(\mathrm{Al}_{2}\left(\mathrm{SO}_{4}\right)_{3} \cdot 18 \mathrm{H}_{2} \mathrm{O} \frac{\text { Heat }}{-18 \mathrm{H}_{2} \mathrm{O}}-\mathrm{A} \stackrel{800^{\circ} \mathrm{C}}{\longrightarrow} \mathrm{B}+\mathrm{C}\) 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 \(\mathrm{MgCl}_{2} .6 \mathrm{H}_{2} \mathrm{O}, \quad \mathrm{CaCl}_{2} \cdot 6 \mathrm{H}_{2} \mathrm{O}, \quad \mathrm{BaCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}\) 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

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) 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

If \(\mathrm{NaOH}\) is added to an aqueous solution of \(\mathrm{Zn}^{2+}\) ions, a white precipitate appears and on adding excess \(\mathrm{NaOH}\), the precipitate dissolves. In this solution zinc exists in the (a) anionic part (b) cationic part (c) both in anionic and cationic parts (d) there is no zinc left in the solution

Sodium amalgam is useful as (a) catalyst (b) oxidizing agent (c) bleaching agent (d) reducing agent

When sodium chloride is electrolyzed in Nelson's cell, hydrogen is liberated at cathode and not sodium, because (a) \(\mathrm{H}^{+}\)does not react with water (b) \(\mathrm{H}^{+}\)has lower electrode potential (c) \(\mathrm{H}^{+}\)has greater mobility than \(\mathrm{Na}^{+}\) (d) \(\mathrm{H}^{+}\)is smaller than \(\mathrm{Na}^{+}\)

\(2 \mathrm{~g}\) of aluminium is treated separately with excess of dilute \(\mathrm{H}_{2} \mathrm{SO}_{4}\) and excess of \(\mathrm{NaOH}\). The ratio of the volumes of hydrogen evolved is (a) \(1: 1\) (b) \(1: 2\) (c) \(2: 1\) (d) \(2: 3\)

Which of the following reactions written here are correct? (1) \(\mathrm{B}+\mathrm{NaOH} \longrightarrow 2 \mathrm{Na}_{3} \mathrm{BO}_{3}+\mathrm{H}_{2}\) (2) \(\mathrm{P}_{4}+\mathrm{NaOH}+\mathrm{H}_{2} \mathrm{O} \longrightarrow \mathrm{NaH}_{2} \mathrm{PO}_{2}+\mathrm{PH}_{3}\) (3) \(\mathrm{S}+\mathrm{NaOH} \longrightarrow \mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}+\mathrm{Na}_{2} \mathrm{~S}+\mathrm{H}_{2} \mathrm{O}\) (a) 1 only (b) 3 only (c) 2 and 3 (d) 1,2 and 3

Match the following: List I List II 1\. Sorel's cement (i) \(\mathrm{MgCl}_{2}\) 2\. Albite (ii) \(\mathrm{MgO}\) 3\. A salt of carnalite (iii) \(\mathrm{NaAlSi}_{3} \mathrm{O}_{8}\) 4\. Glauber's salt (iv) \(\mathrm{Na}_{2} \mathrm{SO}_{4} \cdot 10 \mathrm{H}_{2} \mathrm{O}\) The correct matching is: \(\begin{array}{llll}1 & 2 & 3 & 4\end{array}\) (a) (ii) (iii) (iv) (i) (b) (iv) (ii) (ii) (i) (c) (iii) (ii) (i) (iv) (d) (ii) (iii) (i) (iv)

Aluminium is more reactive than iron because its standard reduction potential is higher. Still aluminium is less easily corrdoed than iron because (a) Al reacts with atmospheric carbon dioxide to form a self protective layer of \(\mathrm{Al}_{2} \mathrm{O}_{3}\) (b) it has higher reducing power and forms a self protective layer of \(\mathrm{Al}_{2} \mathrm{O}_{3}\) (c) it has higher reducing power and does not react with oxygen so easily (d) both (a) and (b)

Some large white transparent crystals are left out in a bowl for several days. They are then observed to have changed their form into white powder. The crystals may have been of (a) calcium oxide (b) sodium carbonate (c) ammonium chloride (d) sodium chloride

The dissolution of \(\mathrm{Al}(\mathrm{OH})_{3}\) by a solution of \(\mathrm{NaOH}\) results in the formation of (a) \(\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{6}(\mathrm{OH})_{3}\right]\) (b) \(\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{4}(\mathrm{OH})\right]^{2+}\) (c) \(\left.\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{2}(\mathrm{OH})\right]\right]\) (d) \(\left[\mathrm{Al}\left(\mathrm{H}_{2} \mathrm{O}\right)_{3}(\mathrm{OH})_{3}\right]\)