Question

title = q2a8 consider the following processes: (i) making kool-aid™ by dissolving kool-aid™ mix and sugar in water (ii) carbonating water by pressurization with carbon dioxide (iii) corrosion of metal on your car (iv) burning your chemistry textbook (v) condensation of water vapor from your breath on a mirror which of these processes are correctly referred to as a \physical change\?
options:

• (i), (iii) and (v)
• (ii) and (iii)
• (ii) and (iv)
• (ii), (iii), (iv), and (v)
• (i), (ii), and (v)

Explanation:

1. Analyze each process:

• (i) Dissolving Kool - Aid mix and sugar in water: This is a physical change as no new substance is formed (it's a solution formation, a physical process of mixing).
• (ii) Carbonating water by pressurizing with \(CO_2\): When \(CO_2\) dissolves in water under pressure, and when the pressure is released, it can come out. The dissolution of \(CO_2\) in water (under pressure for carbonation) is a physical change as the \(CO_2\) can be reversed (like in a soda bottle, when you open it, \(CO_2\) escapes).
• (iii) Corrosion of metal: Corrosion (like rusting of iron) is a chemical change as new substances (oxides) are formed.
• (iv) Burning a textbook: Burning involves combustion, which is a chemical change (new substances like \(CO_2\), water vapor, and ash are formed).
• (v) Condensation of water vapor: This is a physical change as water vapor (gas) changes to liquid water, and no new substance is formed.

1. Now, identify the physical changes: (i), (ii), and (v) are physical changes.

Answer:

(i), (ii), and (v) (the last option in the list: (i), (ii), and (v))