Problem 1
The number of significant figures for the three numbers \(161 \mathrm{~cm}, 0.161 \mathrm{~cm}, 0.0161 \mathrm{~cm}\) are (a) 2,3 and 4 respectively (b) 3,3 and 3 respectively (c) 3,5 and 4 respectively (d) 3,4 and 4 respectively
Problem 3
Which has maximum number of oxygen atoms? (a) \(1 \mathrm{gm}\) of \(\mathrm{O}\) (b) \(1 \mathrm{gm}\) of \(\mathrm{O}_{2}\) (c) \(1 \mathrm{gm}\) of \(\mathrm{O}_{3}\) (d) All have same no.of O-atoms
Problem 4
A mole of any substance is related to (a) number of particles (b) volume of gaseous substances (c) mass of a substance (d) all of these
Problem 6
The number of gram molecules of oxygen in \(6.02 \times\) \(10^{24} \mathrm{CO}\) molecules is (a) 1 gm molecules (b) 2 gm molecules (c) 5 gm molecules (d) 8 gm molecules
Problem 7
The number of oxygen atoms in \(4.4 \mathrm{~g}\) of \(\mathrm{CO}_{2}\) is (a) \(6 \times 10^{23}\) (b) \(11 \times 10^{23}\) (c) \(12 \times 10^{23}\) (d) \(1.2 \times 10^{23}\)
Problem 9
The number of moles of \(\mathrm{KCl}\) in \(1000 \mathrm{~mL}\) of 3 molar solution is (a) 2 (b) 3 (c) 4 (d) 6
Problem 11
The correct relationship between molecular mass and vapour density is (a) V.D. \(=2 \mathrm{M}\) (b) V.D. \(=\frac{M}{2}\) (c) \(\mathrm{M}=(\mathrm{V} \cdot \mathrm{D} .)^{\frac{1}{2}}\) (d) V.D. \(=\mathrm{M}^{2}\)
Problem 13
How many moles of potassium chlorate should be decomposed completely to obtain \(67.2\) litres of oxygen at STP? (a) 1 (b) 2 (c) 3 (d) 4
Problem 15
The hydrated salt \(\mathrm{Na}_{2} \mathrm{CO}_{3} \cdot \mathrm{n} \mathrm{H}_{2} \mathrm{O}\) undergoes \(63 \%\) loss in mass on heating and becomes anhydrous. The value of \(\mathrm{n}\) is (a) 4 (b) 6 (c) 8 (d) 10
Problem 16
The vapour density of a mixture having \(\mathrm{NO}_{2}\) and \(\mathrm{N}_{2} \mathrm{O}_{4}\) is \(27.6 .\) The mole fraction \(\mathrm{NO}_{2}\) in the mixture is (a) \(1.6\) (b) \(0.8\) (c) \(2.4\) (d) \(0.6\)
