Question

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

Answer 1

Hint: To solve this question, we must first understand the differences between compounds and mixtures. On the basis of their definitions, we must analyse the constituents of the given options and then determine which of them is a compound.

Complete Step-by-Step Answer:
Before we move forward with the solution of the given question, let us first understand some important basic concepts.
Compounds can be understood as chemical substances which are formed by chemical reactions between two or more constituent reacting atoms or molecules. These reactions result in the rearrangements in the atoms present in the reactants to give completely new products. The molecules of compounds have fixed ratios of the constituent atoms which are held together by chemical bonds.
There are substances that also contain constituent atoms and molecules in undefined ratios. These constituents are just physically placed together and are not chemically bonded together. Such substances are known as mixtures.
On the other hand, there are some substances known as allotropes. Allotropes can be understood as a chemical property which enables some chemical elements to exist in different forms in the same physical state.

Now let us go through the options given.
1.Graphite: Graphite is an allotrope of carbon. It is formed by arranging carbon atoms in hexagonal structures which are placed together in a single lattice layer. Multiple lattice layers are then stacked one above the other, which totally form the graphite structure.
2.Producer gas: producer gas is formed by mixing gases like carbon monoxide, hydrogen, and nitrogen. These gases do not react with each other and hence they do not form any chemical bonds. Thus, producer gas is a mixture.
3.Cement: Cement is formed by mixing natural materials like clay, limestone, sand, shale, etc. these substances do not react with each other and hence cement is a mixture of these substances.
4.Marble: marble mainly consists of a compound known as calcium carbonate along wit some impurities. Since marble is almost made completely from calcium carbonate, it can be considered to be a compound.
Hence, Option D is the correct option

Note: Slabs and blocks of marble are used for stair treads, floor tiles, facing stone, cemetery stones, window sills, ashlars, sculptures, benches, paving stones and many other uses. Marble is cut using block cutters or multiwire. Multi Wire cutters are used to obtain slabs.