Question

Which of the following is a compound?
A. Graphite
B. Producer gas
C. Cement
D. Marble

Answer 1

Hint: To solve this problem, we need to know what a compound is. A compound is formed by combining two or more elements in a fixed ratio. Compounds are a classification of matter.

Complete step by step answer:
Graphite is the stable pure form of elemental carbon in a solid state. Graphite only contains carbon atoms as constituents. So, this is an example of an element and not a compound according to the classification of matter.
Producer gas is formed by mixing of carbon monoxide and hydrogen gases. These are not forming any chemical bond with each other but it exists as a mixture of carbon monoxide and hydrogen. This is an example of mixtures according to the classification of matter.
Cement is an example of a solid homogeneous mixture of calcium compounds. So, it will not be a compound according to the classification of matter.
The constituent particle of marble is Calcium carbonate. Calcium carbonate is formed by the combining of elements like calcium, carbon and oxygen by a chemical bond in a fixed proportion. So, Marble is an example of a compound.

So, the correct answer is Option D.

Note:
Students may get confused with mixtures and compounds. The main difference between mixtures and compounds is the mixture is formed by the physical mixing of two different substances while compound is formed by combining two or more elements chemically.