Which statement best describes how the products of a chemical reaction are identified using the phenol red test and the splint test?

• A. The phenol red test confirms the presence of oxygen by turning blue, and the splint test detects carbon dioxide by extinguishing a burning splint.
• B. The phenol red test detects the presence of carbon dioxide by a color change, while the splint test identifies oxygen by relighting a glowing splint.
• C. Both the phenol red test and the splint test are used to detect hydrogen gas produced in a reaction.
• D. The phenol red test and the splint test are only used to identify acids and bases, not reaction products.

Answer: (B)

Verified step by step guidance

1. Step 1: Understand the purpose of the phenol red test. Phenol red is a pH indicator that changes color depending on the acidity or basicity of a solution. When carbon dioxide (CO\_2) dissolves in water, it forms carbonic acid, which lowers the pH and causes phenol red to change color, typically from red to yellow, indicating the presence of CO\_2.
2. Step 2: Understand the splint test. The splint test is used to identify oxygen gas (O\_2). A glowing splint (a small piece of wood that is smoldering but not burning) will relight or burst into flame in the presence of oxygen because oxygen supports combustion.
3. Step 3: Analyze the statements given in the problem. The phenol red test is not used to detect oxygen by turning blue; it detects carbon dioxide by a color change due to pH change. The splint test does not detect carbon dioxide by extinguishing a burning splint; instead, carbon dioxide extinguishes flames but does not relight a glowing splint.
4. Step 4: Match the correct description to the tests. The phenol red test detects carbon dioxide by a color change (due to acid formation), and the splint test identifies oxygen by relighting a glowing splint.
5. Step 5: Conclude that the correct statement is: 'The phenol red test detects the presence of carbon dioxide by a color change, while the splint test identifies oxygen by relighting a glowing splint.'