Question 1: Define a strong acid and give an example relevant to sports science.

Answer: A strong acid is an acid that completely dissociates in solution; an example is hydrochloric acid (HCl), used in pH buffering in sports drinks.

Question 2: Explain how weak acids differ from strong acids in terms of dissociation and their typical use in sports nutrition.

Answer: Weak acids only partially dissociate in solution, providing gradual pH changes; they are used in sports drinks to maintain stable acidity and prevent rapid pH shifts during exercise.

Question 3: Describe the mechanism by which a strong acid affects the pH of a sports drink.

Answer: A strong acid fully dissociates, releasing a high concentration of hydrogen ions, which lowers the pH and increases acidity.

Question 1: Calculate the pH of a 0.01 mol/dm³ hydrochloric acid solution used in a sports drink. (Use pH = -log[H⁺])

Answer: 2

Question 2: A weak acetic acid solution used in a sports supplement has an initial concentration of 0.1 mol/dm³. If the acid dissociation constant (Ka) is 1.8 × 10⁻⁵, estimate the pH of the solution assuming weak acid dissociation equilibrium.

Answer: Approximately 3.0

Question 1: Outline the safety precautions that should be taken when handling strong acids in a sports science laboratory.

Answer: Wear appropriate personal protective equipment such as gloves and goggles, work in a well-ventilated area, and handle acids with care to prevent spills and burns.

Question 2: Describe an experiment to compare the pH stability of a weak acid-based sports drink versus a strong acid-based solution, including variables to control.

Answer: Students could prepare equal concentrations of a weak acid (e.g., acetic acid) and a strong acid (e.g., HCl), then monitor pH changes over time under identical temperature and stirring conditions. Variables to control include concentration, temperature, and mixing speed.

Question 1: A sports scientist measures the pH of two energy drinks: Drink A (pH 3.2) and Drink B (pH 5.8). Which drink contains a stronger acid, and what does this imply about their dissociation? Explain briefly.

Answer: Drink A contains the stronger acid, implying it dissociates more completely, leading to a more acidic environment which can affect muscle performance and buffering capacity.

Question 1: Explain how the use of weak acids in sports drinks can help athletes manage muscle pH during intense exercise. (6 marks)

Answer: Weak acids dissociate partially, providing a gradual release of hydrogen ions, which helps maintain a stable pH in muscle tissues during exercise. This buffering capacity prevents rapid acidification, reducing fatigue and muscle soreness, thus improving performance.

Question 1: Discuss how the understanding of strong versus weak acids has contributed to the development of effective sports drinks and supplements.

Answer: Knowledge of acid strength allows formulation of sports drinks that buffer pH effectively, enhancing athletic performance and recovery. Using weak acids provides gradual pH regulation, avoiding sudden acidity changes that could impair muscle function.