Question

Which of the following pairs illustrates the law of multiple proportions?

• A. $P{H}_3$, $HCl$
• B. $PbO$, $Pb{O}_2$
• C. $H_{2}S$, $S{O}_2$
• D. $CuC{l}_2$, $CuS{O}_4$

Answer 1

The correct option is B $PbO$, $Pb{O}_2$

the law of multiple proportions.: two elements combine to form more than one compound and the masses of one element that combine with a fixed mass of the other element is in the ratio of small whole numbers.

So all elements are same only the mass ratio of reactants varies the product formation.

thus in $PbO$ and $Pb{O}_2$ the reactants are $Pb$ and $O_2$ that combine in different ratio. other options do not have all the elements common.

option B is correct