Final answer:
The law of multiple proportions explains the relationship between carbon dioxide (CO₂) and carbon monoxide (CO), where CO₂ has twice as much oxygen per carbon than CO.
Step-by-step explanation:
The relationship between the pair of compounds mentioned can be explained by the law of multiple proportions. According to this law, when two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers. For instance, compounds A and B have different proportions of carbon to oxygen. Compound A, carbon dioxide (CO₂), has twice as much oxygen per unit of carbon compared to compound B, carbon monoxide (CO). This clearly demonstrates the law of multiple proportions and highlights the predictable ratios in which elements combine to form different compounds