Correct Option
The correct option is (c).
Explanation
Matter is broadly classified into pure substances (elements and compounds) and mixtures. The distinction lies in the nature of the bonding between constituents and the methods required to separate them. Physical methods separate mixtures, while chemical methods are required to break down compounds.
Statement-wise Analysis
- Statement 1 is Incorrect. Sodium chloride (common salt) can be separated from water by the physical process of evaporation. When a salt solution is heated, the water evaporates, leaving the solid salt behind. This is a standard method for separating soluble solids from liquids.
- Statement 2 is Correct. Sodium chloride is a pure substance (specifically, a compound). It has a fixed chemical composition ($NaCl$). While it can be separated from a mixture (like salt water) by physical means, the compound itself cannot be broken down into its chemical constituents (Sodium and Chlorine) by physical processes. Electrochemical or chemical reactions are required to separate the elements in a compound.
- Statement 3 is Correct. Soft drinks are mixtures. They are solutions containing water, dissolved carbon dioxide, sugar, and various flavoring agents. Since the composition can vary and the components retain their individual properties, it is classified as a mixture, not a pure substance.
Key Takeaway
Pure substances (elements and compounds) have fixed compositions and cannot be separated into constituents by physical methods. Mixtures contain two or more substances mixed in any proportion and can be separated using physical techniques like evaporation, filtration, or distillation.