Chapter 1

A gaseous mixture contains \(\mathrm{O}_{2}\) and \(\mathrm{N}_{2}\) in the ratio \(1: 4\) by weight. Then the ratio of their number of molecules in the mixture is (a) \(3: 32\) (b) \(7: 32\) (c) \(1: 4\) (d) \(3: 16\)

\(1 \mathrm{cc} \mathrm{N}_{2} \mathrm{O}\) at NTP contains (a) \(\frac{1.32}{224} \times 10^{23}\) electrons (b) \(\frac{6.02}{22400} \times 10^{23}\) molecules (c) \(\frac{1.8}{224} \times 10^{22}\) atoms (d) all of these

\(0.30 \mathrm{~g}\) of a volatile liquid displaces \(90.0 \mathrm{~cm}^{3}\) of air at STP in the Victor Meyer's method. The molecular mass of the liquid is (a) \(54.44 \mathrm{~g}\) (b) \(34.64 \mathrm{~g}\) (c) \(64.76 \mathrm{~g}\) (d) \(74.66 \mathrm{~g}\)

A 5 molar solution of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) is diluted from 1 litre to a volume of 10 litres, the normality of the solution will be (a) \(0.5 \mathrm{~N}\) (b) \(1 \mathrm{~N}\) (c) \(2.5 \mathrm{~N}\) (d) \(5 \mathrm{~N}\)

If \(0.50\) mole of \(\mathrm{BaCl}_{2}\) is mixed with \(0.20 \mathrm{~mole}\) 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 (a) \(0.10\) (b) \(0.20\) (c) \(0.30\) (d) \(0.40\)

The equivalent weight of \(\mathrm{MnSO}_{4}\) is half its molecular weight when it is converted to (a) \(\mathrm{MnO}\) (b) \(\mathrm{MnO}_{4}^{2-}\) (c) \(\mathrm{MnO}_{2}\) (d) \(\mathrm{MnO}_{4}^{-}\)

An aqueous solution of \(6.3 \mathrm{~g}\) oxalic acid dehydrate is made up to \(250 \mathrm{ml}\). The volume of \(0.1 \mathrm{~N} \mathrm{NaOH}\) required to completely neutralize \(10 \mathrm{~mL}\) of this solution is (a) \(4 \mathrm{~mL}\) (b) \(20 \mathrm{~mL}\) (c) \(40 \mathrm{~mL}\) (d) \(60 \mathrm{~mL}\)

In the standardization of \(\mathrm{Na}_{2} \mathrm{~S}_{2} \mathrm{O}_{3}\) using \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) by iodometry, the equivalent weight of \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) is (a) same as mol. wt (b) \(\frac{\text { mol. wt }}{2}\) (c) \(\frac{\text { mol. wt }}{4}\) (d) \(\frac{\text { mol } w t}{6}\)

The number of molecules in \(4.25 \mathrm{~g}\) of ammonia is (a) \(1.5 \times 10^{23}\) (b) \(2.5 \times 10^{23}\) (c) \(3.5 \times 10^{23}\) (d) \(15 \times 10^{23}\)

The weight of a single atom of oxygen is (a) \(5.057 \times 10^{23} \mathrm{~g}\) (b) \(1.556 \times 10^{23} \mathrm{~g}\) (c) \(2.656 \times 10^{-23} \mathrm{~g}\) (d) \(4.538 \times 10^{-23} \mathrm{~g}\)

From the complete decomposition of \(20 \mathrm{~g} \mathrm{CaCO}_{3}\) at STP the volume of \(\mathrm{CO}_{2}\) obtained is (a) \(2.24 \mathrm{~L}\) (b) \(4.48 \mathrm{~L}\) (c) \(44.8 \mathrm{~L}\) (d) \(48.4 \mathrm{~L}\)

\(5 \mathrm{~g}\) of \(\mathrm{CH}_{3} \mathrm{COOH}\) is dissolved in one litre of ethanol. Suppose there is no reaction between them. If the density of ethanol is \(0.789 \mathrm{~g} / \mathrm{mL}\) then the molality of resulting solution is (a) \(0.0256\) (b) \(0.1056\) (c) \(1.1288\) (d) \(0.2076\)

\(800 \mathrm{~g}\) of a \(40 \%\) solution by weight was cooled. \(100 \mathrm{~g}\) of solute precipitated. The percentage composition of remaining solution is (a) \(31.4 \%\) (b) \(57.6 \%\) (c) \(45.8 \%\) (d) \(41.4 \%\)

\(0.25 \mathrm{~mol}\) of \(\mathrm{P}_{4}\) molecules contains ___ atoms. (a) \(1.764 \times 10^{23}\) (b) \(6.02 \times 10^{19}\) (c) \(6.023 \times 10^{23}\) (d) \(8.086 \times 10^{23}\)

How many grams of \(\mathrm{CH}_{3} \mathrm{OH}\) would have to be added to water to prepare \(150 \mathrm{~mL}\) of a solution that is \(2.0 \mathrm{M}\) \(\mathrm{CH}_{3} \mathrm{OH} ?\) (a) \(9.6 \mathrm{~g}\) (b) \(906 \mathrm{~g}\) (c) \(4.3 \times 10^{2} \mathrm{~g}\) (d) \(9.6 \times 10^{3} \mathrm{~g}\)

The oxide of an element contains \(67.67 \%\) of oxygen and the vapour density of its volatile chloride is 79 . Equivalent weight of the element is (a) \(2.46\) (b) \(3.82\) (c) \(4.36\) (d) \(4.96\)

The molar concentration of \(20 \mathrm{~g}\) of \(\mathrm{NaOH}\) present in 5 litre of solution is (a) \(0.1 \mathrm{~mol} / \mathrm{L}\) (b) \(0.2 \mathrm{~mol} / \mathrm{L}\) (c) \(\mathrm{v} 1.0 \mathrm{~mol} / \mathrm{L}\) (d) \(2.0 \mathrm{~mol} / \mathrm{L}\)

Maximum number of molecules will be in (a) \(1 \mathrm{~g}\) of \(\mathrm{H}_{2}\) (b) \(10 \mathrm{~g}\) of \(\mathrm{H}_{2}\) (c) \(22 \mathrm{~g}\) of \(\mathrm{O}_{2}\) (d) \(44 \mathrm{~g}\) of \(\mathrm{CO}_{2}\)

Haemoglobin contains \(0.33 \%\) of iron by weight. The molecular weight of haemoglobin is approximately 67200 . The number of iron atom (at. wt of \(\mathrm{Fe}\) is 56 ) present in one molecule of haemoglobin are (a) 1 (b) 6 (c) 4 (d) 2

The equivalent weight of phosphoric acid \(\left(\mathrm{H}_{3} \mathrm{PO}_{4}\right)\) in the reaction: \(\mathrm{NaOH}+\mathrm{H}_{3} \mathrm{PO}_{4} \longrightarrow \mathrm{NaH}_{2} \mathrm{PO}_{4}+\mathrm{H}_{2} \mathrm{O}\) is (a) 89 (b) 98 (c) 59 (d) 29

\(4 \mathrm{~g}\) caustic soda is dissolved in \(100 \mathrm{cc}\) of solution. The normality of solution is (a) 1 (b) \(0.8\) (c) \(0.6\) (d) \(0.10\)

When a mixture of \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) and \(\mathrm{NaH} \mathrm{CO}_{3}\) was heated at \(423 \mathrm{~K} 112 \mathrm{ml}\) of \(\mathrm{CO}_{2}\) was formed only. What is the \(\%\) of \(\mathrm{Na}_{2} \mathrm{CO}_{3}\) here in the mixture? (a) \(84 \%\) (b) \(16 \%\) (c) \(32 \%\) (d) \(68 \%\)

The mass of \(\mathrm{BaCO}_{3}\) formed where excess of \(\mathrm{CO}_{2}\) is passed through a solution having \(0.205\) mole of Ba \((\mathrm{OH})_{2}\) is? (a) \(40.5 \mathrm{gm}\) (b) \(20.25 \mathrm{gm}\) (c) \(81 \mathrm{gm}\) (d) \(4.05 \mathrm{gm}\)

The normality of orthophosphoric acid having purity of \(70 \%\) be weight and specific gravity \(1.54\) is (a) \(11 \mathrm{~N}\) (b) \(22 \mathrm{~N}\) (c) \(33 \mathrm{~N}\) (d) \(44 \mathrm{~N}\)

\(10^{21}\) molecules are removed from \(200 \mathrm{mg}\) of \(\mathrm{CO}_{2}\). The moles of \(\mathrm{CO}_{2}\) left are (a) \(2.88 \times 10^{-3}\) (b) \(28.8 \times 10^{-3}\) (c) \(288 \times 10^{-3}\) (d) \(28.8 \times 10^{3}\)

What is the volume (in litres) of oxygen at STP required for complete combustion of \(32 \mathrm{~g}\) of \(\mathrm{CH}_{4}\) ? (mol. wt of \(\mathrm{CH}_{4}=16\) ) (a) \(89.6\) (b) \(189.6\) (c) \(98.4\) (d) \(169.5\)

Two grams of sulphur is completely burnt in oxygen to form \(\mathrm{SO}_{2}\), In this reaction, what is the volume (in litres) of oxygen consumed at STP? (At. wt of sulphur and oxygen are 32 and 16 respectively) (a) \(\frac{22.414}{16}\) (b) \(\frac{16}{22.441}\) (c) \(\frac{32.414}{18}\) (d) \(\frac{42.414}{16}\)

How many water molecules are there in one drop of water (volume \(=0.0018 \mathrm{~mL}\) ) at room temperature? (a) \(4.86 \times 10^{17}\) (b) \(6.023 \times 10^{24}\) (c) \(2.584 \times 10^{19}\) (d) \(6.023 \times 10^{19}\)

'X' litres of carbon monoxide is present at STP. It is completely oxidized to \(\mathrm{CO}_{2} .\) The volume of \(\mathrm{CO}_{2}\) formed is \(11.207\) litres at STP. What is the value of ' \(\mathrm{X}\) ' in litres? (a) \(32.2\) (b) \(21.2\) (c) \(10.2\) (d) \(11.2\)

Which has maximum number of molecules? (a) \(7 \mathrm{~g} \mathrm{~N}_{2}\) (b) \(2 \mathrm{~g} \mathrm{H}_{2}\) (c) \(18 \mathrm{~g} \mathrm{NO}_{2}\) (d) \(16 \mathrm{~g} \mathrm{O}_{2}\)

One mole of fluorine is reacted with two mole of hot and concentrated KOH. The products formed are \(\mathrm{KF}, \mathrm{H}_{2} \mathrm{O}\) and \(\mathrm{O}_{2} .\) The molar ratio of \(\mathrm{KF}, \mathrm{H}_{2} \mathrm{O}\) and \(\mathrm{O}_{2}\) respectively is (a) \(1: 2: 1\) (b) \(1: 2: 2\) (c) \(0.5: 1: 2\) (d) \(2: 1: 0.5\)

The total number of protons in \(10 \mathrm{~g}\) of calcium carbonate is \(\left(\mathrm{N}_{0}=6.023 \times 10^{25}\right)\) (a) \(3.01 \times 10^{24}\) (b) \(4.06 \times 10^{24}\) (c) \(30.1 \times 10^{24}\) (d) \(3.01 \times 10^{23}\)

What is the volume (in litre) of oxygen required at STP to completely convert \(1.5\) moles of sulphur to sulphur dioxide? (a) \(33.6\) (b) \(43.6\) (c) \(11.2\) (d) \(23.6\)

In acidic medium, dichromate ion oxidize ferrous ion to ferric ion. If the gram molecular weight of potassium dichromate is \(294 \mathrm{~g}\), its equivalent weight is (a) 19 (b) 49 (c) 99 (d) 294

\(10 \mathrm{~g}\) of \(\mathrm{CaCO}_{3}\) is completely decomposed to \(\mathrm{X}\) and \(\mathrm{CaO} . \mathrm{X}\) is passed into an aqueous solution containing one mole of sodium carbonate. What is the number of moles of sodium bicarbonate formed? (Mol. wt of \(\mathrm{CaCO}_{3}=100, \mathrm{Na}_{2} \mathrm{CO}_{3}=106\) \(\left.\mathrm{NaHCO}_{3}=84\right)\) (a) \(0.010\) (b) \(0.2\) (c) \(0.4\) (d) 10

The number of moles of \(\mathrm{KMnO}_{4}\) reduced by one mole of KI in alkaline medium is (a) 2 (b) 1 (c) 5 (d) 6

How many grams of dibasic acid (mol. wt 200) should be present in \(100 \mathrm{~mL}\) of the aqueous solution to give \(0.1\) normality? (a) \(1 \mathrm{~g}\) (b) \(1.5 \mathrm{~g}\) (c) \(0.5 \mathrm{~g}\) (d) \(20 \mathrm{~g}\)

'X' gram of calcium carbonate was completely burnt in air. The weight of solid residue formed is \(28 \mathrm{~g}\). What is the value of ' \(\mathrm{X}\) ' (in grams)? (a) 50 (b) 100 (c) 150 (d) 200

One mole of acidified \(\mathrm{K}_{2} \mathrm{Cr}_{2} \mathrm{O}_{7}\) on reaction with excess KI will liberate \(\ldots \ldots\) moles (s) of \(\mathrm{I}_{2}\). (a) 2 (b) 3 (c) 6 (d) 7

\(0.59 \mathrm{~g}\) of the silver salt of an organic acid (molar mass 210 ) on ignition gave \(0.36 \mathrm{~g}\) of pure silver. The basicity of the acid is (a) 2 (b) 3 (c) 4 (d) 5

\(\mathrm{KMnO}_{4}(\mathrm{~mol} . \mathrm{wt}=158)\) oxidizes oxalic acid in acidic medium to \(\mathrm{CO}_{2}\) and water as follows. \(5 \mathrm{C}_{2} \mathrm{O}_{4}^{2-}+2 \mathrm{MnO}_{4}^{-}+16 \mathrm{H}^{+} \longrightarrow 10 \mathrm{CO}_{2}+\) \(2 \mathrm{Mn}^{2+}+8 \mathrm{H}_{2} \mathrm{O}\) What is the equivalent weight of \(\mathrm{KMnO}_{4} ?\) (a) 158 (b) \(31.6\) (c) \(39.5\) (d) 79

Sodium bicarbonate on heating decomposes to form sodium carbonate, \(\mathrm{CO}_{2}\) and water. If \(0.2\) moles of sodium bicarbonate is completely decomposed, how many moles of sodium carbonate is formed? (a) \(0.1\) (b) \(0.2\) (c) \(0.05\) (d) \(0.025\)

A purified pepsin was subjected to amino acid analysis. The amino acid present in the smallest amount was lysine, \(\mathrm{C}_{6} \mathrm{H}_{14} \mathrm{~N}_{2} \mathrm{O}_{2}\) and the amount of lysine was found to be \(0.431 \mathrm{~g}\) per \(100 \mathrm{~g}\) of protein. The minimum molecular mass of protein is (a) \(34 \mathrm{u}\) (b) \(3400 \mathrm{u}\) (c) \(34,000 \mathrm{u}\) (d) \(3400,000 \mathrm{u}\)

Find the number of valence electrons present in \(0.53\) gram of \(\mathrm{Na}_{2} \mathrm{CO}_{3}\). (a) \(3.01 \times 10^{23}\) (b) \(1.2046 \times 10^{23}\) (c) \(12.046 \times 10^{23}\) (d) \(6.023 \times 10^{23}\)

If \(3.02 \times 10^{19}\) molecules are removed from \(98 \mathrm{mg}\) of \(\mathrm{H}_{2} \mathrm{SO}_{4}\), then the number of moles of \(\mathrm{H}_{2} \mathrm{SO}_{4}\) left are (a) \(0.1 \times 10^{-3}\) (b) \(5 \times 10^{-4}\) (c) \(1.2 \times 10^{-4}\) (d) \(1.5 \times 10^{-3}\)

A metal oxide has the formula \(\mathrm{M}_{2} \mathrm{O}_{3} .\) It can be reduced by hydrogen to give free metal and water. \(0.1595 \mathrm{~g}\) of the metal oxide requires \(6 \mathrm{mg}\) of hydrogen for complete reduction. What is the atomic weight of metal? (a) \(54.4\) (b) \(46.56\) (c) \(55.8\) (d) \(58.5\)

A chloride of a metal (M) has \(65.5 \%\) of chlorine. 100 \(\mathrm{ml}\) of vapour of the chloride of metal at STP weighs \(0.72 \mathrm{~g}\). The molecular formula of this metal chloride is (a) \(\mathrm{MCl}_{3}\) (b) \(\mathrm{MCl}_{4}\) (c) \(\mathrm{M}_{2} \mathrm{Cl}_{3}\) (d) \(\mathrm{MCl}_{3}\)

The strength of \(0.01 \mathrm{M} \mathrm{Na}_{2} \mathrm{CO}_{3}\) solution in terms of molality is nearly \(\quad\) when the density of the solution is \(1.1 \mathrm{~g} / \mathrm{mL}\) (a) \(9 \times 10^{-3}\) (b) \(1.8 \times 10^{-3}\) (c) \(4.5 \times 10^{-3}\) (d) \(1.1 \times 10^{-3}\)

One mole of magnesium in the vapour state absorbed \(1200 \mathrm{~kJ} \mathrm{~mol}^{-1}\) of energy. If the first and second ionization energies of \(\mathrm{Mg}\) are 750 and \(1450 \mathrm{~kJ} \mathrm{~mol}^{-1}\) respectively, the final composition of the mixture is (a) \(86 \% \mathrm{Mg}^{+}+14 \% \mathrm{Mg}^{2+}\) (b) \(36 \% \mathrm{Mg}^{+}+64 \% \mathrm{Mg}^{2+}\) (c) \(69 \% \mathrm{Mg}^{+}+31 \% \mathrm{Mg}^{2+}\) (d) \(31 \% \mathrm{Mg}^{+}+69 \% \mathrm{Mg}^{2+}\)

A metal oxide has the formula \(\mathrm{Z}_{2} \mathrm{O}_{3}\). It can be reduced by hydrogen to give free metal and water. \(0.1596 \mathrm{~g}\) of the metal oxide requires \(6 \mathrm{mg}\) of hydrogen for complete reduction. The atomic weight of the metal is (a) \(55.8\) (b) \(65.8\) (c) \(6.58\) (d) \(15.9\)