Chapter 7

In \(\mathrm{Ni}(\mathrm{CO})_{4}\), the oxidation state of \(\mathrm{Ni}\) is (a) 4 (b) zero (c) 2 (d) 8

The \(\mathrm{pH}\) value of decinormal solution of \(\mathrm{NH}_{4} \mathrm{OH}\), which is \(20 \%\) ionized, is (a) \(13.70\) (b) 14,70 (c) \(12.30\) (d) \(12.95\)

Which one of the following is an example of disproportionation? (a) \(2 \mathrm{NH}_{3}+3 \mathrm{CuO} \rightarrow 3 \mathrm{Cu}+3 \mathrm{H}_{2} \mathrm{O}+\mathrm{N}_{2}\) (b) \(5 \mathrm{Hl}+\mathrm{HlO}_{3} \rightarrow 3 \mathrm{H}_{2} \mathrm{O}+3 \mathrm{l}_{2}\) (c) \(\mathrm{I}_{2}+2 \mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3} \rightarrow 2 \mathrm{Nal}+\mathrm{Na}_{2} \mathrm{~S}_{4} \mathrm{O}_{6}\) (d) \(\mathrm{P}_{4}+3 \mathrm{NaOH}+3 \mathrm{H}_{2} \mathrm{O} \rightarrow 3 \mathrm{NaH}_{2} \mathrm{PO}_{2}+\mathrm{PH}_{3}\)

The solubility of \(\mathrm{AgCl}\) in \(0.1 \mathrm{M} \mathrm{NaCl}\) will (a) increase (b) decrease (c) remain unchanged (d) \(\mathrm{AgCl}\) will dissociate completely

Bromine reacts with hot aqueous alkali to give bromide and bromate. What is the change that is brought about in oxidation state of bromine to bromate? (a) \(-1\) to \(+5\) (b) 0 to \(+5\) (c) \(-\underline{1}\) to \(+7\) (d) none of these

Twenty milliliters of \(0.1 \mathrm{~N} \mathrm{HCl}\) is mixed with \(20 \mathrm{~mL}\) of \(0.1 \mathrm{~N} \mathrm{KOH}\) solution; the \(\mathrm{pH}\) of the solution will be (a) 0 (b) \(\underline{2}\) (c) \(\underline{7}\) (d) 9

The oxidation state of chlorine in \(\mathrm{KClO}_{4}\) is (a) \(+7\) (b) \(-7\) (c) \(+1\) (d) \(-1\)

Of the given anions, the strongest Bronsted base is: (a) \(\mathrm{ClO}^{-}\) (b) \(\mathrm{ClO}_{2}^{-}\) (c) \(\mathrm{ClO}_{3}^{-}\) (d) \(\mathrm{ClO}_{4}^{-}\)

In the reaction: \(3 \mathrm{Cl}_{2}+6 \mathrm{NaOH} \rightarrow 5 \mathrm{NaCl}+\mathrm{NaClO}_{3}+3 \mathrm{H}_{2} \mathrm{O}\) (a) \(\mathrm{Cl}_{2}\) is oxidized only (b) \(\mathrm{Cl}_{2}\) is reduced only (c) \(\mathrm{Cl}_{2}\) is both oxidized and reduced (d) \(\mathrm{Cl}_{2}\) is neither oxidized nor reduced

The oxidation number of \(\mathrm{Cr}\) in \(\mathrm{CrO}_{5}\) is \(+3\) (b) \(+5\) (c) \(+\underline{6}\) (d) \(\overline{0}\)

The \(\mathrm{pH}\) of \(0.1 \mathrm{M}\) solution of the following salts increases in the order of (a) \(\mathrm{NaCl}<\mathrm{NH}_{4} \mathrm{Cl}<\mathrm{NaCN}<\mathrm{HCl}\) (b) \(\mathrm{HCl}<\mathrm{NH}_{4} \mathrm{Cl}<\mathrm{NaCl}<\mathrm{NaCN}\) (c) \(\mathrm{NaCN}<\mathrm{NH}_{4} \mathrm{Cl}<\mathrm{NaCl}<\mathrm{HCl}\) (d) \(\mathrm{HCl}<\mathrm{NaCl}<\mathrm{NaCN}<\mathrm{NH}_{4} \mathrm{Cl}\)

In which one of the following compounds the oxidation number of oxygen is positive? (a) \(\mathrm{H}_{2} \mathrm{O}_{2}\) (b) \(\mathrm{Na}-\mathrm{O}_{2}\) (c) \(\mathrm{OF}_{2}\) (d) \(\mathrm{H}_{2} \mathrm{O}\)

A white salt is readily soluble in water and gives a colourless solution with a pH of about \(9 .\) The salt would be (a) \(\mathrm{NH}_{4} \mathrm{NO}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{COONa}\) (c) \(\mathrm{CH}_{3} \mathrm{COONH}_{4}\) (d) \(\mathrm{CaCO}_{3}\)

Of the following clements, which one has the same oxidation state in all of its compounds? (a) Hydrogen (b) Fluorine (c) Carbon (d) Oxygen

An acid solution of \(\mathrm{pH} 6\) is diluted hundred times. The \(\mathrm{pH}\) of the solution becomes (a) 6 (b) \(6.95\) (c) 4 (d) 8

The oxidation number of sulphur in \(S_{3}, S_{2} F_{2}\) and \(H_{2} S\) respectively are (a) \(0,+1\) and \(-2\) (b) \(+2,+1\) and \(-2\) (c) \(0,+1\) and \(+2\) (d) \(-2,+1\) and \(-2\)

When \(\mathrm{NH}_{4} \mathrm{Cl}\) is added to \(\mathrm{NH}_{4} \mathrm{OH}\) solution, the dissociation of ammonium hydroxide is reduced. It is due to (a) common ion effect (b) hydrolysis (c) oxidation (d) reduction

The oxidation number of C in HCN and HNC respectively are (a) \(+2,+2\) (b) \(+2,+4\) (c) \(+4,+4\) (d) \(-2,-2\)

The equivalent weight of \(\mathrm{Cr}_{2} \mathrm{O}_{7}^{2-}\) in an acidic medium is (a) \(M / 2\) (b) \(M / 3\) (c) \(\mathrm{M} / 9\) (d) \(M / 6\)

The \(\mathrm{pH}\) of \(0.001 \mathrm{M}\) solution of \(\mathrm{HCl}\) is (a) \(1.0\) (b) 3 (c) \(4.0\) (d) \(5.0\)

The \(\mathrm{p} K_{a}\) of acetylsalicyclic acid (aspirin) is \(3.5 .\) The \(\mathrm{pH}\) of gastric juice in human stomach is about \(2-3\) and the \(\mathrm{pH}\) in the small intestine is about 8. Aspirin will be : (a) unionized in the small intestine and in the stomach (b) completely ionized in the small intestine and in the stomach (c) ionized in the stomach and almost unionized in the small intestine (d) ionized in the small intestine and almost unionized in the stomach

Among the following, the oxidation number of chlorine is the highest in (a) \(\mathrm{Cl}_{3} \mathrm{O}\) (b) \(\mathrm{ClO}_{2}\) (c) \(\mathrm{CrO}_{2} \mathrm{Cl}_{2}\) (d) \(\mathrm{Mg}\left(\mathrm{ClO}_{4}\right)_{2}\)

If the solubility of \(\mathrm{PbBr}_{2}\) is ' \(S^{\prime}\) gram mol per litre, considering \(80 \%\) ionization, its ionic product is (a) \(2 S^{3}\) (b) \(4 s^{2}\) (c) \(45^{3}\) (d) \(2.5^{-1}\)

A nolution of \(\mathrm{KMnO}_{4}\) is reduced to \(\mathrm{MnO}_{2}\). The normality of solution is \(0.6\). Its motanty will be (a) \(1.8 \mathrm{M}\) (b) \(0.6 \mathrm{M}\) (c) \(0.1 \mathrm{M}\) (d) \(0.2 \mathrm{M}\)

On the basis of structure, the oxidation of two \(\mathrm{Cl}\) atoms in \(\mathrm{CaOCl}_{2}\) respectively are (a) \(-1\) and \(+1\) (b) \(+2,-2\) (c) \(-2,+2\) (d) \(-1\) and \(+3\)

Which of the following cannot act as a buffer mixture? (a) \(\mathrm{Na}_{2} \mathrm{CO}_{3}+\mathrm{H}_{2} \mathrm{CO}_{3}\) (b) \(\mathrm{HCN}+\mathrm{NaOH}\) (c) \(\mathrm{Na}_{2} \mathrm{CO}_{3}+\mathrm{HCl}\) (d) \(\mathrm{NH}_{4} \mathrm{Cl}+\mathrm{HCl}\)

Oxidation number of \(\mathrm{N}\) in \(\mathrm{NH}_{4} \mathrm{NO}_{3}\) is (a) \(-3\) (b) \(+5\) (c) \(-3\) and \(+5\)

The decreasing order of strength of the following bases is: (a) \(\mathrm{Cl}, \mathrm{CH}_{3} \mathrm{COO}^{-}, \mathrm{NH}_{3}\) (b) \(\mathrm{CH}_{3} \mathrm{COO}^{-}, \mathrm{NH}_{3}, \mathrm{Cl}^{-}\) (c) \(\mathrm{CH}_{3} \mathrm{COO}^{-}, \mathrm{Cl}^{-}, \mathrm{NH}_{3}\) (d) \(\mathrm{NH}_{3}, \mathrm{CH}_{3} \mathrm{COO}^{-}, \mathrm{Cl}^{-}\)

A sample of \(2.5\) mol of hydrazine \(\left(\mathrm{N}_{2} \mathrm{H}_{4}\right)\) loses 25 mol of electrons on being converted to a new compound \(X\). Assuming that there is no loss of nitrogen in the formation of the new compound, what is the oxidation number of nitrogen in compound \(X ?\) (a) \(-1\) (b) \(-2\) (c) \(+3\) ??. 4

Which oxyacid of chlorine cannot undergo disproportionation? (a) \(\mathrm{HClO}\) (b) \(\mathrm{HClO}_{2}\) (c) \(\mathrm{HClO}_{4}\) (d) \(\mathrm{HClO}\)

Ostwald's dilution law is applicable in the case of the solution of (a) \(\mathrm{NaCl}\) (b) \(\mathrm{NaOH}\) (c) \(\mathrm{H}_{2} \mathrm{SO}_{4}\) (d) \(\mathrm{CH}_{3} \mathrm{COOH}\)

Oxidation number of fluorine in \(\mathrm{F}_{2} \mathrm{O}\) is (a) \(+1\) (b) \(+2\) (c) \(-1\) (d) \(-2\)

Predict whether or not a precipitate will form when \(100 \mathrm{~mL}\) of a \(0.1 \mathrm{M} \mathrm{Pb}^{2+}\) solution is mixed with \(100 \mathrm{~mL}\) of a \(0.3 \mathrm{M} \mathrm{Cl}^{-}\)solution. Given: \(K_{\text {ip }}\left(\mathrm{PbCl}_{2}\right)=1.6 \times 10^{-5} \mathrm{M}^{3}\) (a) yes (b) no (c) data insufficient (d) may be

What is the coefficient of oxalate ion in the following reaction? $$ \mathrm{MnO}_{4}^{-}+\mathrm{C}_{2} \mathrm{O}_{4}^{2-}+\mathrm{H}^{*} \rightarrow \mathrm{Mn}^{2+}+\mathrm{CO}_{2}+\mathrm{H}_{2} \mathrm{O} $$ (a) \(\overline{4}\) (b) 2 (c) 3 (d) 5

The solubility of mercurous chloride in water will be given as (a) \(S=K_{s p}\) (b) \(S=K_{\mathrm{m}} / 4\) (c) \(S=\left(K_{s p} / 4\right)^{1 / 2}\) (d) \(S=\left(K_{\mathrm{sp}} / 4\right)^{1 / 3}\)

The equivalent weight of phosphoric acid \(\left(\mathrm{H}_{3} \mathrm{PO}_{4}\right)\) in the reaction $$ \mathrm{NaOH}+\mathrm{H}_{3} \mathrm{PO}_{4} \rightarrow \mathrm{NaH}_{2} \mathrm{PO}_{4}+\mathrm{H}_{2} \mathrm{O} \text { is } $$ (a) 59 (b) 49 (c) 25 (d) 98

The oxidation state of the most electronegative element in the products of the reaction between \(\mathrm{BaO}_{2}\) and \(\mathrm{H}_{2} \mathrm{SO}_{4}\) are (a) 0 and \(-1\) (b) \(-1\) and \(-2\) (c) \(-2\) and 0 (d) \(-2\) and \(+1\)

The oxidation state of chromium in \(\mathrm{Cr}(\mathrm{CO})_{6}\) is (a) \(\overline{0}\) (b) \(+2\) (c) \(-2\) (d) \(+6\)

The oxidation state of iodine in \(\mathrm{IPO}_{4}\) is (a) \(+1\) (b) \(+3\) (c) \(+5\) (d) \(+7\)

The aqueous solution of \(\mathrm{AICl}_{3}\) is acidic due to: (a) cation hydrolysis (b) anion hydrolysis (c) hydrolysis of both the ions (d) dissociation

\(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}+\mathrm{HI} \rightarrow \mathrm{K} \mathrm{I}+\mathrm{Cr} \mathrm{I}_{3}+\mathrm{H}_{2} \mathrm{O}+\mathrm{I}_{2}\) When the above equation is balanced, what is the coefficient for \(\mathrm{Crl}_{3}\) and \(\mathrm{HI} ?\) (a) 4 and 7 (b) 3 and 10 (c) 2 and 14 (d) 1 and 12

Oxidation number of \(\mathrm{Cl}\) in \(\mathrm{NOClO}_{4}\) and \(\mathrm{NOCl}\) is respectively (a) \(-\mid\) and \(+1\) (b) \(+\mathrm{I}\) and \(-1\) (c) \(+7\) and \(-1\) (d) \(+5\) and \(+1\)

Which has the highest \(\mathrm{pH}\) ? (a) \(\mathrm{CH}_{3} \mathrm{COONH}_{4}\) (b) \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) (c) \(\mathrm{NH}_{4} \mathrm{Cl}\) (d) \(\mathrm{NaNO}_{3}\)

Oxidation numbers of iodine in iodate and periodate are respectively (a) \(+3\) and \(+5\) (b) \(+1\) and \(+3\) (c) \(+5\) and \(+7\) (d) \(+3\) and \(+7\)

Calculate the \(\mathrm{OH}\) ion concentration of \(\mathrm{NaOH}\) of which \(\mathrm{pH}\) is 12 (a) \(10^{-2}\) (b) \(10^{-12}\) (c) \(10^{-9}\) (d) \(10^{2}\)

Oxidation number of \(\mathrm{Br}\) and \(\mathrm{V}\) in \(\mathrm{V}\left(\mathrm{BrO}_{2}\right)_{2}\) are respectively (a) \(+3\) and \(+5\) (b) \(+1\) and \(+3\) (c) \(+5\) and \(+3\) (d) \(+3\) and \(+2\)

The solubility of \(\mathrm{BaSO}_{4}\) in water is \(2.33 \times 10^{-3} \mathrm{~g} \mathrm{~L}^{-1}\). Its solubility product will be (molecular weight of \(\mathrm{BaSO}_{4}=233\) ). (a) \(1 \times 10^{-5}\) (b) \(1 \times 10^{-10}\) (c) \(1 \times 10^{-15}\) (i) \(1 \times 10^{-20}\)

The solubility product of \(\mathrm{Agl}\) at \(25^{\circ} \mathrm{C}\) is \(1.0 \times 10^{-16}\) \(\mathrm{mol}^{2} \mathrm{~L}^{-2}\). The solubility of Agl in \(10^{-4} \mathrm{~N}\) solution of \(\mathrm{KI}\) at \(25^{\mathrm{"}} \mathrm{C}\) is approximately (in \(\left.\operatorname{mol} \mathrm{L}^{-1}\right)\) (a) \(1.0 \times 10^{-16}\) (b) \(1.0 \times 10^{-12}\) (c) \(1.0 \times 10^{-10}\) (b) \(1.0 \times 10^{-12}\) (d) \(1.0 \times 10^{-8}\)

When iodine is passed through sodium thiosulphate, it is decolourised and sodium tetrathionate is formed. What is the change in the oxidation number of a sulphur atom in the reaction ? (a) \(1 / 2\) (b) \(3 / 2\) (c) 2 (d) 1 How many mole

When rain is accomplished by a thunderstorm, the collected rain water will have \(\mathrm{pH}\) value (a) slightly higher than that when the thunderstorm is not there (b) uninfluenced by occurrence of thunderstorm (c) which depends on the amount of dust in air (d) slightly lower than that of rain water without thunderstorm