Question: which one of the following combinations illustrate law of reciprocal proportions?
Answer: According to law of reciprocal proportions, if there are three atoms A, B and C, and if A forms molecule by combining with B and separately with C also, then if B and C also combine together, Thus in part (C), there are three atoms in all which are C, S and O. which is 2:1 and it is a multiple ratio.