Molecular composition
- Molecular composition refers to the arrangement , type and ratio of atoms in molecules of chemical substance and chemical substance varies when chemicals are added or subtracted from substance when the ratio of substances changes or when other chemical changes occur.
- A chemical is defined as a substance with a distinct chemical makeup and structure.
- Chemicals can exist in a variety of states, such as solid or liquid. They can change their condition as a result of several circumstances such as pressure, temperature, and so on.
- The chemist Joseph Proust laid the way for the Law of Constant Composition, which is a foundation of contemporary chemistry.
- A chemical substance's makeup is predetermined. “All samples of a compound have the same composition,” Proust concluded, “i.e., all samples have the same proportion, by mass, of the elements present in the compound.”
- The molecular composition of a molecule can be represented as the empirical and molecular formula of the compound.
- Empirical formula represents the bonded atoms with the simplest whole number. It does not indicate the exact number of atoms in the molecule bonded.
- Molecular formulas represent the exact number of atoms present in the molecule. The mass percent of each element and empirical formula can be used to interpret the molecular formula.
Molecular Composition Questions
Question 1: Molecular composition is the ____________ of atoms in molecules of chemical substance.
(a) Arrangement
(b) Chemical properties
(c) Type of atoms
(d) Both 1 and 3
Solution : Molecular composition is the arrangement and type of atoms in molecules of a chemical substance.
Answer : (d)
Question 2: Chemical composition is the ratio of ____________ changes occurring in chemical reaction.
(a) Physical
(b) Chemical
(c) Temporary
(d) Both physical and chemical changes.
Solution : Chemical composition is the ratio of chemical changes occurring in chemical reaction.
Answer : (b)
Question 3: Write the empirical formula of the given molecular formula.
(a) C6H6
(b) C2H5OH
(c) C6H12O6
Answer: The empirical formula of any molecular formula represents the simplest whole number ratio of all bonded elements. Thus, the empirical formula must be:
(a) C6H6 = CH
(b) C2H5OH = C2H6O
(c) C6H12O6 = CH2O
Frequently Asked Questions
What is the definition for molecules?
Group of two or more atoms held together by chemical bonds is called a molecule. A molecule has specific chemical properties based on its composition and bonding. A molecule can be made up of similar or different atoms.
For example, Oxygen molecule (
Is chemical composition the same as chemical formula?
The chemical composition and chemical formula are two different things but tell us about the same thing, the kind and number of atoms a molecule is made of.
For example, chemical formula of water 
Which are the two most important macromolecules of a cell?
Nucleic acid and proteins are the two most important macromolecules. Nucleic acids (DNA, RNA) carry all the important genetic information and Proteins are required for the structure, function, and regulation of the body's different tissues and organs.
What is a percentage composition?
Percentage composition is the percentage of an element present in a compound. It is calculated by dividing the mass of a single element in one mole of a compound by the mass of one mole of the whole compound.
