Question

Two chemical species X and Y combine together to form a product P which contains both X and Y,

X+Y→P, X and Y cannot be broken down into simpler substances by simple chemical reactions. Which of the following concerning the species X, Y and P are correct?
(i) P is a compound
(ii) X and Y are compounds
(iii) X and Y are elements
(iv) P has a fixed composition

(a) (i), (ii) and (iii)
(b) (i), (ii) and (iv)
(c) (ii), (iii) and (iv)
(d) (i), (iii) and (iv)

Answer 1

Product P is a compound formed from elements X and Y, which have a fixed composition in P. X and Y are elements because they cannot be broken into simpler substances. The correct answer is option (d): (i), (iii), and (iv).

Step-by-step explanation:

When chemical species X and Y, which cannot be broken down into simpler substances by simple chemical reactions, combine to form product P, several conclusions can be drawn about the nature of X, Y, and P. The product P is a compound because it contains two or more different elements chemically combined in a fixed proportion, and it has properties different from X and Y. Since X and Y cannot be broken down into simpler substances, they are likely elements, as the definition of an element is a substance that cannot be broken down by chemical methods into a simpler substance. Furthermore, P, as a compound, will have a fixed composition, ensuring that it retains the same proportions of X and Y no matter how much of it is produced.

Therefore, the correct options that describe the species X, Y, and P are (i) P is a compound, (iii) X and Y are elements, and (iv) P has a fixed composition. Option (ii) is incorrect because X and Y are not compounds; they are elements that combine to form the compound P. Hence, the appropriate response to the question would be option (d): (i), (iii), and (iv).