Explain the use of oxygen in welding and mountain climbing, the right to safety info on flammable substances, two other uses of oxygen, and three classes of fire.

Here are the solutions to the questions:

65. b) Explain the use of oxygen in the following activities: i) Welding: Oxygen is used in oxy-fuel welding to produce a very hot flame when combined with a fuel gas (like acetylene). This high temperature is necessary to melt and join metals. ii) Mountain climbing: Mountain climbers use oxygen tanks because the atmospheric pressure and oxygen levels are significantly lower at high altitudes. Supplemental oxygen helps them breathe adequately and prevents altitude sickness.

66. Every person has a right to safety and access to information on flammable substances because it enables them to take necessary precautions to prevent accidents, fires, and injuries. This knowledge empowers individuals to protect themselves, their property, and others from potential hazards associated with these substances.

67. Two other uses of oxygen gas in everyday life are:

    • Medical use: Oxygen is administered to patients with respiratory difficulties or in emergency situations to support breathing.
    • Respiration: It is essential for the breathing process in humans and animals, allowing cells to produce energy.

68. Three classes of fire are: i) Class A: Fires involving ordinary combustible materials like wood, paper, cloth. ii) Class B: Fires involving flammable liquids such as gasoline, oil, and paint. iii) Class F (or K): Fires involving cooking oils and fats in appliances.

69. Which of the following arrangements represent a fire triangle: c) Oxygen, fuel and heat

70. Oxygen is collected over water because it is sparingly soluble in water and does not react with water. This method, known as downward displacement of water, is a convenient way to collect gases that are not very soluble.