The refreshing characteristic taste of fizzy drinks is due ot the presence of

Step 1: Analyze the question The question asks what gives fizzy (carbonated) drinks their refreshing, characteristic taste.

Step 2: Explain the concept Fizzy drinks such as soda and mineral water are carbonated. Carbon(IV) oxide gas is dissolved in the liquid under pressure. When you open the bottle, the pressure drops and the gas escapes as bubbles, which is the "fizz".

When CO₂ dissolves in water, it forms a weak acid called carbonic acid:

CO₂ + H₂O ⇌ H₂CO₃

This weak acid gives the slightly sharp, tangy, refreshing taste and the tingling feeling on the tongue.

Step 3: Check each option

• A. Carbon(IV) oxide: Correct. It is the gas that makes the drink fizzy and gives the sharp, refreshing taste.
• B. Glucose: This is a sugar. It adds sweetness, not the fizzy, refreshing character.
• C. Hydrogen: Hydrogen is not used in drinks. It is flammable and not soluble enough to matter.
• D. Sodium citrate: This is a food additive used to regulate acidity or add a slightly salty or sour flavour. It is not responsible for the fizz.

Step 4: Answer The refreshing characteristic taste of fizzy drinks is due to Carbon(IV) oxide, option A.

Exam tip: "Fizzy" or "carbonated" always points to CO₂. Remember "carbonated = carbon dioxide". Also, gas solubility increases with pressure (Henry's law), which is why the drink is bottled under pressure and fizzes when opened.