Question 1: Define the pH scale and explain what the pH value indicates about a solution.

Answer: The pH scale measures the acidity or alkalinity of a solution, ranging from 0 to 14. A pH less than 7 indicates acidity, exactly 7 is neutral, and greater than 7 indicates alkalinity.

Question 2: Describe how hydrogen ion concentration relates to pH levels in a solution.

Answer: The pH of a solution is the negative logarithm of the hydrogen ion concentration; higher hydrogen ion concentration results in lower pH (more acidic), while lower concentration results in higher pH (more alkaline).

Question 1: Calculate the hydrogen ion concentration in a solution with a pH of 3.0. Use the formula: [H⁺] = 10^(-pH).

Answer: 1.0 x 10^(-3) mol/L

Question 2: A solution has a hydrogen ion concentration of 1 x 10^(-8) mol/L. What is its pH?

Answer: 8

Question 1: Describe the main safety precautions to observe when handling strong acids and alkalis in the laboratory.

Answer: Wear protective gloves and goggles, handle acids and alkalis with care to avoid spills, and work in a well-ventilated area.

Question 2: Explain how you would prepare a pH indicator solution for measuring the pH of a sample.

Answer: Dilute a few drops of a universal pH indicator or litmus solution with distilled water to prepare a solution that changes color depending on the pH.

Question 1: A sample of rainwater has a pH of 5.6, while tap water has a pH of 7.0. What does this suggest about the acidity of rainwater compared to tap water?

Answer: Rainwater is slightly more acidic than tap water, indicating it has a higher concentration of hydrogen ions.

Question 2: In an industrial process, a solution's pH is maintained at 9.0 for optimal operation. If the pH drops to 7.0, what could be the possible effects?

Answer: The solution becomes more acidic, which could corrode equipment, affect product quality, or indicate contamination or imbalance in the process.

Question 1: Explain why soil pH is important for crop growth and how farmers might adjust soil pH if it is too acidic or too alkaline.

Answer: Soil pH affects nutrient availability to plants. If soil is too acidic, farmers can add lime (calcium carbonate) to raise pH; if too alkaline, they might add sulfur or ammonium-based fertilizers to lower pH, ensuring optimal conditions for crop growth.

Question 2: Describe how pH measurement is used in the food industry to ensure product safety and quality.

Answer: pH measurement helps monitor acidity or alkalinity in food products, which affects flavor, preservation, and safety. For example, dairy products are tested to prevent spoilage, and processed foods are adjusted to maintain consistent quality and meet safety standards.