The following data are obtained when dinitrogen and dioxygen react together to form different compounds: Mass of dinitrogen Mass of dioxygen (i) 14 g 16 g (ii) 14 g 32 g (iii) 28 g 32 g (iv) 28 g 80 g

Q- 21 The following data are obtained when dinitrogen and dioxygen react together to form
different compounds:
Mass of dinitrogen Mass of dioxygen
(i) 14 g 16 g
(ii) 14 g 32 g
(iii) 28 g 32 g
(iv) 28 g 80 g
Answer :- 
(a) Which law of chemical combination is obeyed by the above experimental data?Give
its statement.
(b) Fill in the blanks in the following conversions:
(i) 1 km = ...................... mm = ...................... pm
(ii) 1 mg = ...................... kg = ...................... ng
(iii) 1 mL = ...................... L = ...................... dm3

Answer :-

A) Fixing the mass of dinitrogen to 28g , mass of dioxygen combined with 32,64,32, and 80 g in the given four oxides . This is the ratio of 1:2:1:5 which is a simple whole number ratio . Hence the given data follow the law of multiple proportions

Law of Multiple Proportions This law was proposed by Dalton in 1803.According to this law, if two elements cancombine to form more than one compound, themasses of one element that combine with afixed mass of the other element, are in theratio of small whole numbers.For example, hydrogen combines with oxygen to form two compounds, namely, water and hydrogen peroxide.
Hydrogen + Oxygen → Water
2g                 16g           18g
Hydrogen + Oxygen → Hydrogen Peroxide
2g               32g                 34g
Here, the masses of oxygen (i.e. 16 g and 32 g)which combine with a fixed mass of hydrogen (2g) bear a simple ratio, i.e. 16:32 or 1: 2. .

B)