Two different samples of pure lead oxide were separately reduced to metallic lead by heating in a st — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question
Question
Two different samples of pure lead oxide were separately reduced to metallic lead by heating in a stream of hydrogen. The weight of lead obtained from one oxide was exactly half the weight of lead obtained from the other oxide for a fixed mass of oxygen. Which of the following statements about this experiment are chemically valid?
💡 Solution & Explanation
Because the mass of lead combining with a fixed mass of oxygen differs by a simple whole number ratio (1:2) across two different compounds of the same elements, this illustrates the Law of Multiple Proportions. Statement A is true. Statement B is false (Constant proportions applies to a *single* compound). Statement C is true, as $PbO$ and $PbO_2$ have Pb masses combining with $32\text{ g}$ of Oxygen in a $207 : 103.5$ (or $2:1$) ratio. Statement D is false (Multiple Proportions was proposed by John Dalton, while Proust proposed Constant Proportions).