Question

Based on the information given, classify each of the pure substances as elements or compounds, or indicate that no such classification is possible because of insufficient information.

Classify whether substance A-K is a element, compound or cannot be classified

Analysis with an elaborate instrument indicates that •Substance A contains two elements. •Substance B and Substance C react to give a new Substance D. •Substance E decomposes upon heating to give Substance F and Substance G. •heating Substance H to 1000°C causes no change. •Substance I cannot be broken down into simpler substances by chemical means. •Substance J cannot be broken down into simpler substances by physical means. •heating Substance K to 500°C causes it to change from a solid to a liquid.

Answer 1

For this question we need to understand difference between element and compound. Both are pure form of substance. The difference is that the element consist of same type of atoms like iron, copper, etc. But compund is madeup of combinatio of different elements in fixed ratio like NaCl, H2O etc.

A. Substance A is a compound as it contain 2 elements.

Substance B and C are element. While substance D is compound as it is made up of 2 elements.

Substance E is compound as it broke into two elements F and G.

Substance H produces no change on heating at high temperature. It could be element. But certain compounds can have decomposition temperature greater than 1000°C.

Substance I is element as it cannot be broke down by chemical means.

Substance J cannot be said as element because there is a limit we can sperate something using physical method. It might be possible that it will break using chemical means.

Substance K melts at 500°C, it can be element or compund using just melting point it is hard to tell.