Compound 1 has a composition of 46.7 mass % of element a and 53.3 mass % of element b. a and b also form a second binary compound (compound 2). if the compositions of the two compounds are consistent with the law of multiple proportions, which of the following compositions could be that of compound 2?

A summary of the Law of multiple proportions is that if A and B form more than one compound, and B1 is the amount of element B which reacts with a fixed mass of A in compound 1, and B2 is the amount of B which reacts with the same fixed mass of B to form compound 2, then the ratio B1:B2 will be small whole numbers.

This law is rather simplistic, and given the range of compounds known today the definition of 'small' is now rather large... but, to answer the question:

in compound one 1.14133g of B reacts with 1g of A. (1.14133=53.3/46.7)