(a) A sample of NaOH weighting 0.38 g is dissolved in water and the solutions is made to 50.0 `cm^(3)` in a volumetric flask. What is the molarity of the solution? (b) State and explain law of multiple proportion.

Explanation

(a) `M=W_(a)/M_(a) xx 100/("volume of solution in ml") = 0.38/40 xx 1000/50 = 0.19 mol L^(-1)`.
(b) Law of multiple proportion states whenever two elements reacts to form or more compounds. The ratio between different weights of one of the element which combine with fixed weight of another is always simple. e.g., nitrogen reacts with oxgyen to form NO and `NO_(2)`. In NO, 14 g of N reacts with 16 g of O. In `NO_(2)`, 14 g of N reacts with 32 g of O. The ratio between weights of oxygen which combine with fixed weight of nitrogen is `16:32`, i.e., 1:2