Problem 12
Given the numbers \(786,0.786\) and \(0.0786\) the number of significant figures for the three numbers is (1) 3,4 and 5 , respectively (2) 3,3 and 3 , respectively (3) 3,3 and 4, respectively (4) 3,4 and 4, respectively
Problem 14
Element \(\mathrm{A}\) reacts with oxygen to form a compound \(\mathrm{A}_{2} \mathrm{O}_{3} .\) If \(0.359\) gram of a compound contains \(0.128 \mathrm{~g}\) of oxygen, atomic weight of \(\mathrm{A}\) will be (1) 51 amu (2) \(43.08\) amu (3) \(49.7\) amu (4) \(47.9 \mathrm{am} \mathrm{u}\)
Problem 15
Oxygen combines with two isotopes of carbon, \({ }^{12} \mathrm{C}\) and \({ }^{14} \mathrm{C}\), to form two samples of carbon dioxide. The data illustrates (1) Law of conservation of mass (2) Law of multiple proportions (3) Law of reciprocal proportions (4) None of these
Problem 16
Suppose that \(\Lambda\) and \(\mathrm{B}\) are two clements which form compounds \(\mathrm{B}_{2} \Lambda_{3}\) and \(\mathrm{B}_{2} \Lambda\), respectively. If \(0.05 \mathrm{~mole}\) of \(\mathrm{B}_{2} \Lambda_{3}\) weighs \(9.0 \mathrm{~g}\) and \(0.10 \mathrm{~mole}\) of \(\mathrm{B}_{2} \Lambda\) weighs \(10 \mathrm{~g}\), then the atomic weight of \(\Lambda\) and \(\mathrm{B}\), respectively is (1) 30 and 40 (2) 40 and 30 (3) 20 and 5 (4) 15 and 20
Problem 17
In the reaction, \(\mathrm{N}_{2}+3 \mathrm{H}_{2} \rightarrow 2 \mathrm{NH}_{3}\), ratio by volume of \(\mathrm{N}_{2}, \mathrm{H}_{2}\) and \(\mathrm{NH}_{3}\) is \(1: 3: 2\). This illustrates (1) definite proportions (2) multiple proportions (3) reciprocal proportions (4) gaseous volumes
Problem 18
One part of an clement \(\mathrm{X}\) combines with two parts of another clement \(\mathrm{Y}\). Six parts of the clement \(\mathrm{Z}\) combines with four parts of clement \(Y\). If \(X\) and \(Y\) combine together, the ratio of their weights will be governed by (1) Law of multiple proportions (2) Law of definite proportions (3) Law of reciprocal proportions (4) Law of conservation of mass
Problem 23
\(\mathrm{II}_{2} \mathrm{~S}\) contain \(5.88 \%\) hydrogen, \(\mathrm{I}_{2} \mathrm{O}\) contain \(11.11 \%\) hydrogen while \(\mathrm{SO}_{2}\) contains \(50 \%\) sulphur. The data illustrate the law of (1) Conservation of mass (2) Constant proportions (3) Multiple proportions (4) Reciprocal proportions
Problem 25
Two elements \(X\) (at mass 16\()\) and \(Y\) (at mass 14\()\) combine to form compounds \(A, B\) and \(C .\) The ratio of different masses of Y which combine with a fixed mass of \(X\) in \(A, B\) and \(C\) is \(1: 3: 5 .\) lf 32 parts by mass of \(X\) combines with 84 parts by mass of \(Y\) and \(B\), then in \(C\). 16 parts by mass of \(\mathrm{X}\) will combine with (1) 14 parts by mass of \(\mathrm{Y}\) (2) 42 parts by mass of \(\mathrm{Y}\) (3) 70 parts by mass of \(\mathrm{Y}\) (4) 84 parts by mass of \(\mathrm{Y}\)
Problem 28
Which one of the following gas contains the same number of molecules as 16 g of oxygen? (1) \(16 \mathrm{~g}\) of \(\mathrm{O}_{3}\) (2) \(16 \mathrm{~g}\) of \(\mathrm{SO}_{2}\) (3) \(32 \mathrm{~g}\) of \(\mathrm{SO}_{2}\) (4) \(\Lambda\) ll the above
Problem 31
\(4.4\) g of an unknown gas occupies \(2.24\) litres of volume at STP. The gas may be (1) carbon dioxide (2) carbon monoxide (3) oxygen (4) sulphur dioxide
