Question

Question 1.21 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


(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

Class XI Some Basic Concepts of Chemistry Page 23

Answer 1

on fixing the mass of H2 as 28g ,the masses of H2 combined are 32g, 64g, 32g, 80g in the given four oxides . if we do ratio of these ,
we get , these are in the simple whole number ratio e.g., 2 : 4 : 2 : 5 .

now,
according to law of multiple proportion: If two elements can be combine to form more than one compound , the masses of one elements that combine with the fixed mass of the other element are in the simple whole number ratio.

here what we observed ,from above data and definition of law of multiple proportion .
e.g.,the given date obey the law of multiple proportion.


(b) (i) ∵ 1 km = 10³ m
∵ 1 m = 10³ mm
∴ 1 km = 10⁶ mm

and ∵ 1 m = 10¹² pm
∴ 1 km = 10¹² * 10³ pm = 10¹⁵ pm.

similarly ,
$(ii) 1 mg = 10^{-6}Kg=10^{-3+9}ng=10^6ng \\ \\ (iii) 1mL=10^{-3}L=10^{-3}dm^3$

Answer 2

this is your correct answer w