Question

The molecular formula is a short form representation of:
A. A compound
B. An element
C. A mixture
D. An alloy

Answer 1

In a chemical compound certain elements combine together in different ratios and this ratio of elements subscripts with the chemical symbol to form a molecular formula. The general form of a molecular formula is ${A_x}{B_y}$.

Complete step by step answer: The molecular formula provides information about the proportions of atoms in a chemical compound. The major constituents of a molecular formula are chemical symbol, numbers, parenthesis, plus (+) and minus (-) sign, brackets, and dashes. The rule for writing a chemical compound for the case of ionic compounds is that the cation (positively charged ion) precedes anion (negatively charged ion). For the case of organic compounds, the carbon and hydrogen are given first preference, and then other elements are written in alphabetical order. For example, in the case of glucose, the molecular formula is given ${C_6}{H_{12}}{O_6}$.
Different elements join together to form a compound, hence the molecular formula cannot represent the short form of an element. Whereas mixtures have variable composition and unlike compounds, they don’t have variable compositions. So molecular formula cannot describe a mixture. Also, an alloy is a mixture and hence they don’t have a chemical formula.
Hence, the correct answer is option A.

Additional Information: The simplest type of molecular formula is known as empirical formula and it indicates the ratio of each element in the molecule.

Note: The molecular formula does not mention any information about the arrangements of an atom and also for one molecular formula different chemical structures exist. For defining a structural arrangement we have the structural formula. The chemical compounds that have different chemical structures but the same chemical structure are known as isomers.