Chapter 1

A solution of two components containing \(n_{1}\) moles of the \(1^{\text {st }}\) component and \(n_{2}\) moles of the \(2^{\text {nd }}\) component is prepared. \(\mathrm{M}_{1}\) and \(\mathrm{M}_{2}\) are the molecular weights of component 1 and 2 respectively. If \(d\) is the density of the solution in \(g \mathrm{~mL}^{-1}, \mathrm{C}_{2}\) is the molarity and \(x_{2}\) is the mole fraction of the \(2^{\text {nd }}\) component, then \(\mathrm{C}_{2}\) can be expressed as: (a) \(\mathrm{C}_{2}=\frac{1000 x_{2}}{\mathrm{M}_{1}+x_{2}\left(\mathrm{M}_{2}-\mathrm{M}_{1}\right)}\) (b) \(\mathrm{C}_{2}=\frac{d x_{2}}{\mathrm{M}_{2}+x_{2}\left(\mathrm{M}_{2}-\mathrm{M}_{1}\right)}\) (c) \(\mathrm{C}_{2}=\frac{1000 d x_{2}}{\mathrm{M}_{1}+x_{2}\left(\mathrm{M}_{2}-\mathrm{M}_{1}\right)}\) (d) \(\mathrm{C}_{2}=\frac{d x_{1}}{\mathrm{M}_{2}+x_{2}\left(\mathrm{M}_{2}-\mathrm{M}_{1}\right)}\)

The ammonia \(\left(\mathrm{NH}_{3}\right)\) released on quantitative reaction of \(0.6 \mathrm{~g}\) urea \(\left(\mathrm{NH}_{2} \mathrm{CONH}_{2}\right)\) with sodium hydroxide \((\mathrm{NaOH})\) can be neutralized by: [Main Jan. 07, 2020 (II)] (a) \(200 \mathrm{~mL}\) of \(0.4 \mathrm{~N} \mathrm{HCl}\) (b) \(200 \mathrm{~mL}\) of \(0.2 \mathrm{~N} \mathrm{HCl}\) (c) \(100 \mathrm{~mL}\) of \(0.2 \mathrm{~N} \mathrm{HCl}\) (d) \(100 \mathrm{~mL}\) of \(0.1 \mathrm{~N} \mathrm{HCl}\)

The average molar mass of chlorine is \(35.5 \mathrm{~g} \mathrm{~mol}^{-1}\). The ratio of \({ }^{35} \mathrm{Cl}\) to \({ }^{37} \mathrm{Cl}\) in naturally occrring chlorine is close to: (a) \(4: 1\) (b) \(3: 1\) (c) \(2: 1\) (d) \(1: 1\)

For a reaction, \(\mathrm{N}_{2}(\mathrm{~g})+3 \mathrm{H}_{2}(\mathrm{~g}) \rightarrow 2 \mathrm{NH}_{3}(\mathrm{~g})\); identify dihydrogen \(\left(\mathrm{H}_{2}\right)\) as a limiting reagent in the following reaction mixtures. [Main April 9, 2019 (I)] (a) \(56 \mathrm{~g}\) of \(\mathrm{N}_{2}+10 \mathrm{~g}\) of \(\mathrm{H}_{2}(\mathrm{~b}) 35 \mathrm{~g}\) of \(\mathrm{N}_{2}+8 \mathrm{~g}\) of \(\mathrm{H}_{2}\) (c) \(28 \mathrm{~g}\) of \(\mathrm{N}_{2}+6 \mathrm{~g}\) of \(\mathrm{H}_{2}\) (d) \(14 \mathrm{~g}\) of \(\mathrm{N}_{2}+4 \mathrm{~g}\) of \(\mathrm{H}_{2}\)

Amongst the following statements, that which was not proposed by Dalton was: (a) Chemical reactions involve reorganization of atoms. These are neither created nor destroyed in a chemical reaction. (b) All the atoms of a given element have identical properties including identical mass. Atoms of different elements differ in mass. (c) When gases combine or reproduced in a chemical reaction they do so in a simple ratio by volume provided all gases are at the same \(\mathrm{T}\) \& P. (d) Matter consists of indivisible atoms.

A \(10 \mathrm{mg}\) effervescent tablet containing sodium bicarbonate and oxalic acid releases \(0.25 \mathrm{~mL}\) of \(\mathrm{CO}_{2}\) at \(\mathrm{T}=298.15 \mathrm{~K}\) and \(\mathrm{P}=1\) bar. If molar volume of \(\mathrm{CO}_{2}\) is \(25.0 \mathrm{~L}\) under such condition, what is the percentage of sodium bicarbonate in each tablet? [Main Jan. 11, 2019 (I)] \(\left[\right.\) Molar mass of \(\left.\mathrm{NaHCO}_{3}=84 \mathrm{~g} \mathrm{~mol}^{-1}\right]\) (a) \(0.84\) (b) \(33.6\) (c) \(16.8\) (d) \(8.4\)

\(8 \mathrm{~g}\) of \(\mathrm{NaOH}\) is dissolved in \(18 \mathrm{~g}\) of \(\mathrm{H}_{2} \mathrm{O} .\) Mole fraction of \(\mathrm{NaOH}\) in solution and molality (in \(\mathrm{mol} \mathrm{kg}^{-1}\) ) of the solution respectively are: (a) \(0.2,22.20\) (b) \(0.2,11.11\) (c) \(0.167,11.11\) (d) \(0.167,22.20\)

The amount of sugar \(\left(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\right)\) required to prepare \(2 \mathrm{~L}\) of its \(0.1 \mathrm{M}\) aqueous solution is: (a) \(136.8 \mathrm{~g}\) (b) \(17.1 \mathrm{~g}\) (c) \(68.4 \mathrm{~g}\) (d) \(34.2 \mathrm{~g}\)

1 gram of a carbonate \(\left(\mathrm{M}_{2} \mathrm{CO}_{3}\right)\) on treatment with excess \(\mathrm{HCl}\) produces \(0.01186\) mole of \(\mathrm{CO}_{2}\). The molar mass of \(\mathrm{M}_{2} \mathrm{CO}_{3}\) in \(\mathrm{g} \mathrm{mol}^{-1}\) is : [Main 2017] (a) 1186 (b) \(84.3\) (c) \(118.6\) (d) \(11.86\)

The ratio of mass percent of \(\mathrm{C}\) and \(\mathrm{H}\) of an organic compound \(\left(\mathrm{C}_{\mathrm{X}} \mathrm{H}_{\mathrm{Y}} \mathrm{O}_{\mathrm{Z}}\right)\) is \(6: 1\). If one molecule of the above compound \(\left(\mathrm{C}_{\mathrm{X}} \mathrm{H}_{\mathrm{Y}} \mathrm{O}_{\mathrm{Z}}\right)\) contains half as much oxygen as required to burn one molecule of compound \(\mathrm{C}_{\mathrm{x}} \mathrm{H}_{\mathrm{Y}}\) completely to \(\mathrm{CO}_{2}\) and \(\mathrm{H}_{2} \mathrm{O}\). The empirical formula of compound \(\mathrm{C}_{\mathrm{x}} \mathrm{H}_{\mathrm{Y}} \mathrm{O}_{\mathrm{Z}}\) is : (a) \(\mathrm{C}_{3} \mathrm{H}_{6} \mathrm{O}_{3}\) (b) \(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}\) (c) \(\mathrm{C}_{3} \mathrm{H}_{4} \mathrm{O}_{2}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{4} \mathrm{O}_{3}\)

The amount of arsenic pentasulphide that can be obtained when \(35.5 \mathrm{~g}\) arsenic acid is treated with excess \(\mathrm{H}_{2} \mathrm{~S}\) in the presence of conc. HCl (assuming \(100 \%\) conversion) is : [Main Online April 9, 2016] (a) \(0.25 \mathrm{~mol}\) (b) \(0.50 \mathrm{~mol}\) (c) \(0.333 \mathrm{~mol}\) (d) \(0.125 \mathrm{~mol}\)

An unknown chlorohydrocarbon has \(3.55 \%\) of chlorine. If each molecule of the hydrocarbon has one chlorine atom only, chlorine atoms present in \(1 \mathrm{~g}\) of chlorohydrocarbon are: (Atomic wt. of \(\mathrm{Cl}=35.5 \mathrm{u}\); Avogadro constant \(=6.023 \times 10^{23} \mathrm{~mol}^{-1}\) (a) \(6.023 \times 10^{9}\) (b) \(6.023 \times 10^{23}\) (c) \(6.023 \times 10^{21}\) (d) \(6.023 \times 10^{20}\)

The most abundant elements by mass in the body of a healthy human adult are : [Main 2017] Oxygen \((61.4 \%) ;\) Carbon \((22.9 \%)\), Hydrogen \((10.0 \%) ;\) and Nitrogen ( \(2.6 \%\) ). The weight which a \(75 \mathrm{~kg}\) person would gain if all \({ }^{1} \mathrm{H}\) atoms are replaced by \({ }^{2} \mathrm{H}\) atoms is (a) \(15 \mathrm{~kg}\) (b) \(37.5 \mathrm{~kg}\) (c) \(7.5 \mathrm{~kg}\) (d) \(10 \mathrm{~kg}\)

A sample of a hydrate of barium chloride weighing \(61 \mathrm{~g}\) was heated until all the water of hydration is removed. The dried sample weighed \(52 \mathrm{~g}\). The formula of the hydrated salt is : (atomic mass, \(\mathrm{Ba}=137\) \(\mathrm{amu}, \mathrm{Cl}=35.5 \mathrm{amu}\) ) [Main Online April 10,2015] (a) \(\mathrm{BaCl}_{2} \cdot 4 \mathrm{H}_{2} \mathrm{O}\) (b) \(\mathrm{BaCl}_{2} .3 \mathrm{H}_{2} \mathrm{O}\) (c) \(\mathrm{BaCl}_{2} \cdot \mathrm{H}_{2} \mathrm{O}\) (d) \(\mathrm{BaCl}_{2} \cdot 2 \mathrm{H}_{2} \mathrm{O}\)

What quantity (in mL) of a \(45 \%\) acid solution of a mono-protic strong acid must be mixed with a \(20 \%\) solution of the same acid to produce \(800 \mathrm{~mL}\) of a \(29.875 \%\) acid solution? (a) 320 (b) 325 (c) 316 (d) 330

Mixture \(X=0.02 \mathrm{~mol}\) of \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{SO}_{4}\right] \mathrm{Br}\) and \(0.02 \mathrm{~mol} \mathrm{o}\) \(\left[\mathrm{Co}\left(\mathrm{NH}_{3}\right)_{5} \mathrm{Br}\right] \mathrm{SO}_{4}\) was prepared in 2 litre of solution. [2003S] 1 litre of mixture \(X+\) excess \(\mathrm{AgNO}_{3} \rightarrow Y\) 1 litre of mixture \(X+\) excess \(\mathrm{BaCl}_{2} \rightarrow Z\) No. of moles of \(Y\) and \(Z\) are (a) \(0.01,0.01\) (b) \(0.02,0.01\) (c) \(0.01,0.02\) (d) \(0.02,0.02\)

At \(300 \mathrm{~K}\) and \(1 \mathrm{~atm}, 15 \mathrm{~mL}\) of a gaseous hydrocarbon requires 375 \(\mathrm{mL}\) air containing \(20 \% \mathrm{O}_{2}\) by volume for complete combustion. After combustion the gases occupy \(330 \mathrm{~mL}\). Assuming that the water formed is in liquid form and the volumes were measured at the same temperature and pressure, the formula of the hydrocarbon is: (a) \(\mathrm{C}_{4} \mathrm{H}_{8}\) (b) \(\mathrm{C}_{4} \mathrm{H}_{10}\) (c) \(\mathrm{C}_{3} \mathrm{H}_{6}\) (d) \(\mathrm{C}_{3} \mathrm{H}_{8}\)

10\. An aqueous solution of \(6.3 \mathrm{~g}\) oxalic acid dihydrate is made up to 250 \(\mathrm{mL}\). The volume of \(0.1 \mathrm{~N} \mathrm{NaOH}\) required to completely neutralize\(\mathrm{mL}\) of this solution is [2001S] (a) \(40 \mathrm{~mL}\) (b) \(20 \mathrm{~mL}\) (c) \(10 \mathrm{~mL}\) (d) \(4 \mathrm{~mL}\)

\(5 \mathrm{~L}\) of an alkane requires \(25 \mathrm{~L}\) of oxygen for its complete combustion. If all volumes are measured at constant temperature and pressure, the alkane is : (a) Isobutane (b) Ethane (c) Butane (d) Propane

The molecular formula of a commercial resin used for exchanging ions in water softening is \(\mathrm{C}_{8} \mathrm{H}_{7} \mathrm{SO}_{3}^{-} \mathrm{Na}^{+}\)(Mol. wt. 206. What would be the maximum uptake of \(\mathrm{Ca}^{2+}\) ions by the resin when expressed in mole per gram resin? (a) \(\frac{2}{309}\) (b) \(\frac{1}{412}\) (c) \(\frac{1}{103}\) (d) \(\frac{1}{206}\)

The normality of \(0.3 \mathrm{M}\) phosphorous acid \(\left(\mathrm{H}_{3} \mathrm{PO}_{3}\right)\) is, [1999 - 2 Marks] (a) \(0.1\) (b) \(0.9\) (c) \(0.3\) (d) \(0.6\)

Choose the incorrect formula out of the four compounds for an element X below :[Main Online April 11, 2015] (a) \(\mathrm{X}_{2} \mathrm{O}_{3}\) (b) \(\mathrm{X}_{2} \mathrm{Cl}_{3}\) (c) \(\mathrm{X}_{2}\left(\mathrm{SO}_{4}\right)_{3}(\mathrm{~d}) \mathrm{XPO}_{4}\)

The equivalent weight of \(\mathrm{MnSO}_{4}\) is half of its molecular weight when it is converted to: [1988-1 Mark] (a) \(\mathrm{Mn}_{2} \mathrm{O}_{3}\) (b) \(\mathrm{MnO}_{2}\) (c) \(\mathrm{MnO}_{4}^{-}\) (d) \(\mathrm{MnO}_{4}^{2-}\)

Dissolving \(120 \mathrm{~g}\) of a compound of (mol. wt. 60) in \(1000 \mathrm{~g}\) of water gave a solution of density \(1.12 \mathrm{~g} / \mathrm{mL}\). The molarity of the solution is: (a) \(1.00 \mathrm{M}\) (b) \(2.00 \mathrm{M}\) (c) \(2.50 \mathrm{M}\) (d) \(4.00 \mathrm{M}\)

In which mode of expression, the concentration of a solution remains independent of temperature? [1988-1 Mark] (a) Molarity (b) Normality (c) Formality (d) Molality

A gaseous hydrocarbon gives upon combustion \(0.72 \mathrm{~g}\) of water and \(3.08 \mathrm{~g}\). of \(\mathrm{CO}_{2}\). The empirical formula of the hydrocarbon is : (a) \(\mathrm{C}_{2} \mathrm{H}_{4}\) (b) \(\mathrm{C}_{3} \mathrm{H}_{4}\) (c) \(\mathrm{C}_{6} \mathrm{H}_{5}\) (d) \(\mathrm{C}_{7} \mathrm{H}_{8}\)

A molal solution is one that contains one mole of a solute in: [1986-1 Mark] (a) \(1000 \mathrm{~g}\) of the solvent (b) one litre of the solvent (c) one litre of the solution (d) \(22.4\) litres of the solution

\(10 \mathrm{~mL}\) of \(2(\mathrm{M}) \mathrm{NaOH}\) solution is added to \(200 \mathrm{~mL}\) of \(0.5\) (M) of \(\mathrm{NaOH}\) solution. What is the final concentration? (a) \(0.57(\mathrm{M})\) (b) \(5.7(\mathrm{M})\) (c) \(11.4(\mathrm{M})\) (d) \(1.14(\mathrm{M})\)

If \(0.50\) mole of \(\mathrm{BaCl}_{2}\) is mixed with \(0.20 \mathrm{~mol}\) of \(\mathrm{Na}_{3} \mathrm{PO}_{4}\), the maximum number of moles of \(\mathrm{Ba}_{3}\left(\mathrm{PO}_{4}\right)_{2}\) that can be formed is [1981 - 1 Mark] (a) \(0.70\) (b) \(0.50\) (c) \(0.20\) (d) \(0.10\)

The density of \(3 \mathrm{M}\) solution of sodium chloride is \(1.252 \mathrm{~g} \mathrm{~mL}^{-1}\). The molality of the solution will be : (molar mass, \(\mathrm{NaCl}=58.5 \mathrm{~g} \mathrm{~mol}^{-1}\) ) (a) \(260 \mathrm{~m}\) (b) \(2.18 \mathrm{~m}\) (c) \(2.79 \mathrm{~m}\) (d) \(3.00 \mathrm{~m}\)

Which has maximum number of atoms? (a) \(24 g\) of \(C(12)\) (b) \(56 \mathrm{~g}\) of \(\mathrm{Fe}(56)\) (c) \(27 \mathrm{~g}\) of \(\mathrm{Al}(27)\) (d) \(108 \mathrm{~g}\) of \(\operatorname{Ag}(108)\)

Which has maximum number of atoms? [2003S] (a) \(24 \mathrm{~g}\) of \(\mathrm{C}(12)\) (b) \(56 \mathrm{~g}\) of \(\mathrm{Fe}(56)\) (c) \(27 \mathrm{~g}\) of \(\mathrm{Al}(27)\)

How many moles of electron weigh one kilogram? (a) \(\frac{1}{206}\) (b) \(\frac{1}{9.108} \times 10^{31}\) (c) \(\frac{6.023}{9.108} \times 10^{54}\) (d) \(\frac{1}{9.108 \times 6.023} \times 10^{8}\)

The minimum number of moles of \(\mathrm{O}_{2}\) required for complete combustion of 1 mole of propane and 2 moles of butane is [Main Sep. 05, 2020 [I)]

If two compounds have the same empirical formula but different molecular fomulae they must have [1987-1 Mark] (a) different percentage composition (b) different molecular weight (c) same viscosity (d) same vapour density

The largest number of molecules is in (a) \(36 \mathrm{~g}\) of water (b) \(28 \mathrm{~g}\) of carbon monoxide (c) \(46 \mathrm{~g}\) of ethyl alcohol (d) \(54 \mathrm{~g}\) of nitrogen pentoxide

The largest number of molecules is in \([1979]\) (a) \(36 \mathrm{~g}\) of water (b) \(28 \mathrm{~g}\) of carbon monoxide (c) \(46 \mathrm{~g}\) of ethyl alcohol (d) \(54 \mathrm{~g}\) of nitrogen pentoxide

A \(20.0 \mathrm{~mL}\) solution containing \(0.2 \mathrm{~g}\) impure \(\mathrm{H}_{2} \mathrm{O}_{2}\) reacts completely with \(0.316 \mathrm{~g}\) of \(\mathrm{KMnO}_{4}\) in acid solution. The purity of \(\mathrm{H}_{2} \mathrm{O}_{2}\) (in \(\%\) ) is (mol. wt. of \(\mathrm{H}_{2} \mathrm{O}_{2}=34 ;\) mol. wt. of \(\mathrm{KMnO}_{4}=158\) ) [Main Sep. 04, 2020 (I)]

The total number of electrons in one molecule of carbon dioxide is [1979] (a) 22 (b) 44 (c) 66 (d) 88

The mass of ammonia in grams produced when \(2.8 \mathrm{~kg}\) of dinitrogen quantitatively reacts with \(1 \mathrm{~kg}\) of dihydrogen is [Main Sep. 04, 2020 (I)]

A gaseous mixture contains oxygen and nitrogen in the ratio of \(1: 4\) by weight. Therefore, the ratio of their number of molecules is \([1979]\) (a) \(1: 4\) (b) \(1: 8\) (c) \(7: 32\) (d) \(3: 16\)

\(27 \mathrm{~g}\) of \(\mathrm{Al}\) will react completely with how many grams of oxygen? [1978] (a) \(8 \mathrm{~g}\) (b) \(16 \mathrm{~g}\) (c) \(32 \mathrm{~g}\) (d) \(24 \mathrm{~g}\)

The mole fraction of glucose \(\left(\mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{6}\right)\) in an aqueous binary solution is \(0.1\). The mass percentage of water in it, to the nearest integer, is [Main Sep. \(\mathbf{0 3}, \mathbf{2 0 2 0}\) (I)]

A compound was found to contain nitrogen and oxygen in the ratio 28 \(\mathrm{g}\) and \(80 \mathrm{~g}\) respectively. The formula of compound is \([1978]\) (a) \(\mathrm{NO}\) (b) \(\mathrm{N}_{2} \mathrm{O}_{3}\) (c) \(\mathrm{N}_{2} \mathrm{O}_{5}\) (d) \(\mathrm{N}_{2} \mathrm{O}_{4}\)

\(6.023 \times 10^{22}\) molecules are present in \(10 \mathrm{~g}\) of a substance ' \(x^{\prime}\). The molarity of a solution containing \(5 \mathrm{~g}\) of substance ' \(x\) ' in \(2 \mathrm{~L}\) solution is \(\times 10^{-3}\) [Main Sep. 03, 2020 [II)]

The volume (in \(\mathrm{mL}\) ) of \(0.1 \mathrm{~N} \mathrm{NaOH}\) required to neutralise \(10 \mathrm{~mL}\) of 0.1 \(\mathrm{N}\) phosphinic acid is $$ \text { [Main Sep. } \mathbf{0 3}, \mathbf{2 0 2 0}[\mathbf{I I})] $$

The molarity of \(\mathrm{HNO}_{3}\) in a sample which has density \(1.4 \mathrm{~g} / \mathrm{mL}\) and mass percentage of \(63 \%\) is (Molecular Weight of \(\mathrm{HNO}_{3}=\) 63)

\(10.30 \mathrm{mg}\) of \(\mathrm{O}_{2}\) is dissolved into a liter of sea water of density \(1.03\) \(\mathrm{g} / \mathrm{mL}\). The concentration of \(\mathrm{O}_{2}\) in ppm is Main Jan. 09. 2020 (II)

If the value of Avogadro number is \(6.023 \times 10^{23} \mathrm{~mol}^{-1}\) and the value of Boltzmann constant is \(1.380 \times 10^{-23} \mathrm{~J} \mathrm{~K}^{-1}\), then the number of significant digits in the calculated value of the universal gas constant is [Adv. 2014]

Ferrous sulphate heptahydrate is used to fortify foods with iron. The amount (in grams) of the salt required to achieve \(10 \mathrm{ppm}\) of iron in \(100 \mathrm{~kg}\) of wheat is .Atomic weight: \(\mathrm{Fe}=55.85 ; \mathrm{S}=32.00 ; \mathrm{O}=\) \(16.00\) [Main Jan. 08, 2020 (I)]