Chapter 21

A metal ' \(\mathrm{M}\) ' reacts with nitrogen gas to afford ' \(\mathrm{M}_{3} \mathrm{~N}^{\prime}\). ' \(\mathrm{M}_{3} \mathrm{~N}\) ' on heating at high temperature gives back ' \(\mathrm{M}\) ' and on reaction with water produces a gas ' \(\mathrm{B}\) '. Gas ' \(\mathrm{B}\) ' reacts with aqueous solution of \(\mathrm{CuSO}_{4}\) to form a deep blue compound. 'M' and 'B' respectively are : [Main Online April 8, 2017] (a) \(\mathrm{Li}\) and \(\mathrm{NH}_{3}\) (b) \(\mathrm{Ba}\) and \(\mathrm{N}_{2}\) (c) \(\mathrm{Na}\) and \(\mathrm{NH}_{3}\) (d) \(\mathrm{Al}\) and \(\mathrm{N}_{2}\)

. \(\mathrm{H}_{2} \mathrm{SO}_{4}\) cannot be used to prepare HBr from NaBr as it : \([19955]\) (a) reacts slowly with \(\mathrm{NaBr}\) (b) oxidises HBr (c) reduces HBr (d) disproportionates \(\mathrm{HBr}_{544} / 1773 \quad-\quad \Theta+\)

Bromine can be liberated from potass?um bromide solution by the action of [1987-1 Mark] (a) Iodine solution (b) Chlorine water (c) Sodium chloride (d) Potassium iodide

Argon is used in arc welding because of its(a) low reactivity with metal (b) ability to lower the melting point of metal (c) flammability (d) high calorific value

The order of the oxidation state of the phosphorus atom in \(\mathrm{H}_{3} \mathrm{PO}_{2}\), \(\mathrm{H}_{3} \mathrm{PO}_{4}, \mathrm{H}_{3} \mathrm{PO}_{3}\) and \(\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{6}\) is [Adv. 2017] (a) \(\mathrm{H}_{3} \mathrm{PO}_{3}>\mathrm{H}_{3} \mathrm{PO}_{2}>\mathrm{H}_{3} \mathrm{PO}_{4}>\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{6}\) (b) \(\mathrm{H}_{3} \mathrm{PO}_{4}>\mathrm{H}_{3} \mathrm{PO}_{2}>\mathrm{H}_{3} \mathrm{PO}_{3}>\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{6}\) (c) \(\mathrm{H}_{3} \mathrm{PO}_{4}>\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{6}>\mathrm{H}_{3} \mathrm{PO}_{3}>\mathrm{H}_{3} \mathrm{PO}_{2}\) (d) \(\mathrm{H}_{3} \mathrm{PO}_{2}>\mathrm{H}_{3} \mathrm{PO}_{3}>\mathrm{H}_{A} \mathrm{P}_{2} \mathrm{O}_{6}>\mathrm{H}_{2} \mathrm{PO}_{4}\)

The compound which gives off oxygen on moderate heating is : [1986-1 Mark] (a) cupric oxide (b) mercuric oxide (c) zinc oxide (d) aluminium oxide

Chlorine acts as a bleaching agent only in presence of [1983-1 Mark] (a) dry air (b) moisture (c) sunlight (d) pure oxygen

The structure of \(\mathrm{XeO}_{3}\) is(a) linear (b) planar (c) pyramidal (d) T-shaped

. The pair in which phosphorus atoms have a formal oxidation state of \(+3\) is: [Main 2016] (a) Orthophosphorous and hypophosphoric acids (b) Pyrophosphorous and pyrophosphoric acids (c) Orthophosphorous and pyrophosphorous acids (d) Pyrophosphorous and hypophosphoric acids

A gas that cannot be collected over water is : [1985-1 Mark] (a) \(\mathrm{N}_{2}\) (b) \(\mathrm{O}_{2}\) (c) \(\mathrm{SO}_{2}\) (d) \(\mathrm{PH}_{3}\)

HBr and HI reduce sulphuric acid, HCl can reduce \(\mathrm{KMnO}_{4}\) and HF can reduce [1981-1 Mark] (a) \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{KMnO}_{4}\) (c) \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) (d) none of the above

\(\mathrm{XeF}_{4}\) and \(\mathrm{XeF}_{6}\) are expected to be(a) oxidizing (b) reducing(c) unreactive (d) strongly basic

Which of the following compound has a P-P bond? [Main Online April 11, 2015] (a) \(\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{5}\) (b) \(\left(\mathrm{HPO}_{3}\right)_{3}\) (c) \(\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{6}\) (d) \(\mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{7}\)

Which of the following is coloured (a) NO (b) \(\mathrm{N}_{2} \mathrm{O}\) (c) \(\mathrm{SO}_{3}\) (d) None

A solution of KBr is treated with each of the following. Which one would liberate bromine [1980] (a) \(\mathrm{Cl}_{2}\) (b) HI (c) \(\mathrm{I}_{2}\) (d) \(\mathrm{SO}_{2}\)

. Write balanced equations for the reactions of the following compounds with water : [2002-5 Marks] (i) \(\mathrm{Al}_{4} \mathrm{C}_{3}\) (ii) \(\mathrm{CaNCN}\) (iii) \(\mathrm{BF}_{3}\) (iv) \(\mathrm{NCl}_{3}\) (v) \(\mathrm{XeF}_{4}\)

Which one of the following does not have a pyramidal shape? [Main Online April 11, 2014] (a) \(\left(\mathrm{CH}_{3}\right)_{3} \mathrm{~N}\) (b) \(\left(\mathrm{SiH}_{3}\right)_{3} \mathrm{~N}\) (c) \(\mathrm{P}\left(\mathrm{CH}_{3}\right)_{3}\) (d) \(\mathrm{P}\left(\mathrm{SiH}_{3}\right)_{3}\)

The total number of compounds having at least one bridging oxo group among the molecules given below is \(. \mathrm{N}_{2} \mathrm{O}_{3}, \mathrm{~N}_{2} \mathrm{O}_{5}, \mathrm{P}_{4} \mathrm{O}_{6}\), \(\mathrm{P}_{4} \mathrm{O}_{7}, \mathrm{H}_{4} \mathrm{P}_{2} \mathrm{O}_{5}, \mathrm{H}_{5} \mathrm{P}_{3} \mathrm{O}_{10}, \mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}, \mathrm{H}_{2} \mathrm{~S}_{2} \mathrm{O}_{5}\) |Adv. 2018]

Which of the following is most stable to heat(a) \(\mathrm{HCl}\) (b) \(\mathrm{HOCl}\) (c) \(\mathrm{HBr}\) (d) HI

Draw the molecular structures of \(\mathrm{XeF}_{2}, \mathrm{XeF}_{4}\) and \(\mathrm{XeO}_{2} \mathrm{~F}_{2}\) indicating the location of lone pair(s) of electrons. [2000-3 Marks]

The product formed in the reaction of \(\mathrm{SOCl}_{2}\) with white phosphorous is [Adv. 2014] (a) \(\mathrm{PCl}_{3}\) (b) \(\mathrm{SO}_{2} \mathrm{Cl}_{2}\) (c) \(\mathrm{SCl}_{2}\) (d) \(\mathrm{POCl}_{3}\)

The amount of water produced (in g) in the oxidation of 1 mole of rhombic sulphur by conc. \(\mathrm{HNO}_{3}\) to a compound with the highest oxidation state of sulphur is \((\) Given data : Molar mass of water = \(\left.18 \mathrm{~g} \mathrm{~mol}^{-1}\right)\) [Adv. 2019]

The number of \(\mathrm{Cl}=\mathrm{O}\) bonds in perchloric acid is, \(\prime\) [Main Sep. 06, 2020 (I)]

Concentrated nitric acid, upon long standing, turns yellow brown due to the formation of [Adv. 2013] (a) NO (b) \(\mathrm{NO}_{2}\) (c) \(\mathrm{N}_{2} \mathrm{O}\) (d) \(\mathrm{N}_{2} \mathrm{O}_{4}\)

The reaction of white phosphorus with aqueous \(\mathrm{NaOH}\) gives phosphine along with another phosphorus containing compound. The reaction type; the oxidation states of phosphorus in phosphine and the other product are respectively [2012] (a) redox reaction; \(-3\) and \(-5\) (b) redox reaction; \(+3\) and \(+5\) (c) disproportionation reaction; \(-3\) and \(+5\) (d) disproportionation reaction: \(-3\) and \(+3\)

The correct statement(s) about \(\mathrm{O}_{3}\) is(are)(a) \(\mathrm{O}-\mathrm{O}\) bond lengths are equal (b) Thermal decomposition of \(\mathrm{O}_{3}\) is endothermic(c) \(\mathrm{O}_{3}\) is diamagnetic in nature (d) \(\mathrm{O}_{3}\) has a bent structure

Chlorine reacts with hot and concentrated \(\mathrm{NaOH}\) and produces compounds \((X)\) and \((Y)\). Compound \((X)\) gives white precipitate with silver nitrate solution. The average bond order between \(\mathrm{Cl}\) and \(\mathrm{O}\) atoms in \((Y)\) is

\text { (d) } \mathrm{NO}, \mathrm{HNO}_{3}, \mathrm{NH}_{4} \mathrm{Cl}, \mathrm{N}_{2}Which ordering of compounds is according to the decreasing order of the oxidation state of nitrogen? [2012] (a) \(\mathrm{HNO}_{3}, \mathrm{NO}, \mathrm{NH}_{4} \mathrm{Cl}, \mathrm{N}_{2}\) (b) \(\mathrm{HNO}_{3}, \mathrm{NO}, \mathrm{N}_{2}, \mathrm{NH}_{4} \mathrm{Cl}\) (c) \(\mathrm{HNO}_{3}, \mathrm{NH}_{4} \mathrm{Cl}, \mathrm{NO}, \mathrm{N}_{2}\)

Which of the following halides react(s) with \(\mathrm{AgNO}_{3}\) (aq) to give a precipitate that dissolves in \(\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}(\mathrm{aq}) ?\) [2012] (a) \(\mathrm{HCl}\) (b) HF (c) \(\mathrm{HBr}\) (d) HI

Extra pure \(\mathrm{N}_{2}\) can be obtained by heating (a) \(\mathrm{NH}_{3}\) with \(\mathrm{CuO}\) (b) \(\mathrm{NH}_{4} \mathrm{NO}_{3}\) (c) \(\left(\mathrm{NH}_{4}\right)_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) (d) \(\mathrm{Ba}\left(\mathrm{N}_{3}\right)_{2}\)

............ acid gives hypo ............... ion. [1988-1 Mark] (hydrobromic, hypobromous, perbromic, bromide, bromite, perbromate)

When \(\mathrm{PbO}_{2}\) reacts with conc. \(\mathrm{HNO}_{3}\), the gas evolved is [2005S] (a) \(\mathrm{NO}_{2}\) (b) \(\mathrm{O}_{2}\) (c) \(\mathrm{N}_{2}\) (d) \(\mathrm{N}_{2} \mathrm{O}\)

Iodine reacts with hot \(\mathrm{NaOH}\) solution. The products are NaI and .......

Blue liquid which is obtained on reacting equimolar amounts of two gases at \(-30^{\circ} \mathrm{C}\) is? [2005S] (a) \(\mathrm{N}_{2} \mathrm{O}\) (b) \(\mathrm{N}_{2} \mathrm{O}_{3}\) (c) \(\mathrm{N}_{2} \mathrm{O}_{4}\) (d) \(\mathrm{N}_{2} \mathrm{O}_{5}\)

Assertion: Nitrogen and oxygen are the main components in the atmosphere but these do not react to form oxides of nitrogen. Reason: The reaction between nitrogen and oxygen requires high temperature.(a) The assertion is incorrect, but the reason is correct (b) Both the assertion and reason are incorrect (c) Both assertion and reason are correct, and the reason is the correct explanation for the assertion (d) Both assertion and reason are correct, but the reason is not the correct explanation for the assertion

Which is the most thermodynamically stable allotropic form of phosphorus?(a) red (b) white (c) black (d) yellow

30\. For \(\mathrm{H}_{3} \mathrm{PO}_{3}\) and \(\mathrm{H}_{3} \mathrm{PO}_{4}\), the correct choice is: [2003S] (a) \(\mathrm{H}_{3} \mathrm{PO}_{3}\) is dibasic and reducing (b) \(\mathrm{H}_{3} \mathrm{PO}_{3}\) is dibasic and non-reducing (c) \(\mathrm{H}_{3} \mathrm{PO}_{4}\) is tribasic and reducing (d) \(\mathrm{H}_{3} \mathrm{PO}_{3}\) is tribasic and non-reducing

. Ammonia can be dried by [2000S] (a) conc. \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (b) \(\mathrm{P}_{4} \mathrm{O}_{10}\) (c) \(\mathrm{CaO}\) (d) anhydrous \(\mathrm{CaCl}_{2}\)

In the contact process for industrial manufacture of sulphuric acid, some amount of sulphuric acid is used as a starting material. Explain briefly. What is the catalyst used in the oxidation of \(\mathrm{SO}_{2}\) ? [1999-4 Marks]

The number of \(\mathrm{P}-\mathrm{O}-\mathrm{P}\) bonds in cyclic metaphosphoric acid is [2000S] (a) zero (b) two (c) three (d) four

THe colour of the \(X_{2}\) molecules of group 17 elements changes gradually from yellow to violet down the group. This is due to [Adv. 2017] (a) The physical state of \(X_{2}\) at room temperature changes from gas to solid down the group (b) Decrease in ionization energy down the group (c) Decrease in \(\pi^{*}-\sigma^{*}\) gap down the group (d) Decrease in HOMO-LUMO gap down the group

The correct statement(s) about the oxoacids, \(\mathrm{HClO}_{4}\) and \(\mathrm{HClO}\), is (are) [Adv. 2017] (a) The central atom in both \(\mathrm{HClO}_{4}\) and \(\mathrm{HClO}\) is \(s p^{3}\) hybridized (b) \(\mathrm{HClO}_{4}\) is more acidic than HClO because of the resonance stabilization of its anion (c) \(\mathrm{HClO}_{4}\) is formed in the reaction between \(\mathrm{Cl}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\) (d) The conjugate base of \(\mathrm{HClO}_{4}\) is weaker base than \(\mathrm{H}_{2} \mathrm{O}\)

. On heating ammonium dichromate, the gas evolved is [1999-2 Marks] (a) oxygen (b) ammonia (c) nitrous oxide (d) nitrogen

\(\mathrm{PbS} \frac{\text { heat } \mathrm{n}}{\mathrm{air}} A+\mathrm{PbS} \underset{\mathrm{B}}{\longrightarrow} \mathrm{Pb}+\mathrm{SO}_{2}\); Identify \(A\) and \(B\)

One mole of calcium phosphide on reaction with excess water gives [1999-2 Marks] (a) one mole of phosphine (b) two moles of phosphoric acid (c) two moles of phosphine (d) one mole of phosphorus pentoxide

Write the two resonance structures of ozone which satisfy the octet rule.

In \(\mathrm{P}_{4} \mathrm{O}_{10}\) each \(\mathrm{P}\) atom is linked with \(\ldots \ldots \ldots . \mathrm{O}\) atoms \([1995 \mathrm{~S}]\) (a) 2 (b) 3 (c) 4 (d) 5

Amongst the trihalides of nitrogen which one is least basic? [1987 - 1 Mark] (a) \(\mathrm{NF}_{3}\) (b) \(\mathrm{NCl}_{3}\) (c) \(\mathrm{NBr}_{3}\) (d) \(\mathrm{NI}_{3}\)

Arrange the following in : \(\mathrm{CO}_{2}, \mathrm{~N}_{2} \mathrm{O}_{5}, \mathrm{SiO}_{2}, \mathrm{SO}_{3}\) in the order of increasing acidic character. [1988-1 Mark]

Statement-1: \(\mathrm{F}\) atom has less electron affinity than \(\mathrm{Cl}\) atom. Statement-2 : Additional electrons are repelled more effectively by \(3 p\) electrons in \(\mathrm{Cl}\) atom than by \(2 p\) electrons in \(\mathrm{F}\) atom [1998 - 2 Marks] (a) Statement-1 is True, Statement-2 isTrue; Statement-2 is a correct explanation for Statement-1 (b) Statement-1 is True, Statement-2 is True; Statement-2 is NOT a correct explanation for Statement-1 (c) Statement- 1 is True, Statement-2 is False (d) Statement- 1 is False, Statement- 2 is True.