Hydrogen Peroxide is an example of
an element.
a compound.
a heterogeneous mixture.
a homogeneous mixture.
- Which of the following is a characteristic of a multi-molecular colloid?
a) Large number of molecules combine to form a particle of colloidal size
b) A large number of atoms aggregate to form a particle of colloidal size
c) Starch solution is an example of multi-molecular colloid
d) multi-molecular colloids are normally of the lyophilic type
The Correct Answer and Explanation is:
1. Hydrogen Peroxide is an example of:
👉 a compound.
Explanation:
Hydrogen peroxide (H₂O₂) is a compound because it is made up of two different elements—hydrogen and oxygen—chemically combined in a fixed ratio. Compounds have consistent properties and can be broken down into simpler substances by chemical means. H₂O₂ differs from a mixture because its components (hydrogen and oxygen) are not physically combined but chemically bonded. It also differs from elements, which consist of only one type of atom, and from mixtures, which can be physically separated and do not have fixed compositions.
2. Which of the following is a characteristic of a multi-molecular colloid?
👉 a) Large number of molecules combine to form a particle of colloidal size
Explanation:
Colloids are mixtures where one substance is dispersed evenly throughout another at the microscopic level, with particle sizes typically between 1 to 1000 nanometers. They can be classified based on the nature and size of the dispersed particles. Multi-molecular colloids are formed when a large number of atoms or small molecules (usually less than 1 nm in size) aggregate to form particles that fall within the colloidal size range.
Option (a) is correct because in multi-molecular colloids, numerous small molecules or atoms come together through van der Waals forces or hydrogen bonding to form larger clusters. These clusters act as the dispersed phase in the colloidal system.
For example, sulfur sol and gold sol are classic multi-molecular colloids. In sulfur sol, sulfur atoms group together to form particles of colloidal dimensions. Similarly, in gold sol, gold atoms aggregate to form colloidal-sized particles.
Other options:
- (b) is more typical of metal atom aggregation, but it’s less general than (a).
- (c) is incorrect because starch solution is a macromolecular colloid, not a multi-molecular colloid.
- (d) is incorrect because multi-molecular colloids are typically lyophobic, not lyophilic. Lyophilic colloids (e.g., gelatin) involve single large molecules and have a strong affinity for the solvent.
Thus, option (a) correctly describes the defining characteristic of multi-molecular colloids
