Question

The wrong statcment among the following is (a) Ozone layer protects the life on earth from \(U \mathrm{~V}\) radiations. (b) CO combines with haemoglobin forming carboxyhaemoglobin and interferes with functioning of haemoglobin leading to death. (c) \(\mathrm{SO}_{2}\) pollution causes decrease in photosynthesis rate. (d) The holes in ozone layer are formed by hydrocarbons.

Short answer

Statement (d) is false.

Step-by-step solution

Understand Each Statement

Examine each given statement to identify its correctness: (a) Ozone layer protects the life on earth from UV radiations. (b) CO combines with haemoglobin forming carboxyhaemoglobin and interferes with functioning of haemoglobin leading to death. (c) SO2 pollution causes decrease in photosynthesis rate. (d) The holes in ozone layer are formed by hydrocarbons.

Verify Statement (a)

Ozone layer indeed protects life on Earth from harmful UV radiation. So, statement (a) is true.

Verify Statement (b)

CO (Carbon Monoxide) combines with haemoglobin to form carboxyhaemoglobin, which inhibits oxygen transport and can lead to death. Hence, statement (b) is true.

Verify Statement (c)

SO2 (Sulphur Dioxide) pollution reduces the rate of photosynthesis by causing damage to plant leaves and affecting the ability of plants to perform photosynthesis. Therefore, statement (c) is true.

Verify Statement (d)

Holes in the ozone layer are primarily caused by chlorofluorocarbons (CFCs), not hydrocarbons. So, statement (d) is false.

Key concepts

Ozone Layer Protection

The ozone layer is like Earth's protective shield. It is located in the stratosphere, about 10-30 kilometers above the Earth's surface. This layer absorbs most of the Sun's harmful ultraviolet (UV) radiation, particularly the UV-B and UV-C types. Without the ozone layer, life on Earth would be exposed to intense solar radiation, leading to increased skin cancer rates, cataracts, and other health issues. It also safeguards ecosystems, including marine life and terrestrial plants, by protecting them from damaging UV rays. So, when we talk about environmental chemistry, the importance of the ozone layer cannot be overstated.

Carboxyhaemoglobin

Carboxyhaemoglobin is formed when carbon monoxide (CO) binds with haemoglobin in the blood. Haemoglobin is responsible for transporting oxygen from the lungs to the rest of the body. However, CO binds to haemoglobin more readily than oxygen, creating carboxyhaemoglobin. This prevents haemoglobin from carrying oxygen, causing cells and tissues to become oxygen-starved. Symptoms of CO poisoning include headache, dizziness, weakness, nausea, and in severe cases, it can lead to death. High levels of carboxyhaemoglobin in the blood can result in a condition known as hypoxia, where body tissues are deprived of adequate oxygen.

Photosynthesis Inhibition

Photosynthesis is the process by which green plants use sunlight to synthesize nutrients from carbon dioxide and water. Sulphur dioxide (SO2) pollution has a detrimental effect on this process. When SO2 is absorbed by plant leaves, it disrupts normal physiological activities. It causes leaf damage, reduces chlorophyll content, and hampers the plant's ability to absorb sunlight efficiently. This leads to a decrease in photosynthetic rate, reducing plant growth and crop yields. The inhibition of photosynthesis can have a cascade effect on ecosystems, affecting not only plants but also the animals and humans who depend on them for food and oxygen.

Ozone Layer Depletion

Ozone layer depletion refers to the thinning of the ozone layer in the Earth’s stratosphere. This thinning is mainly attributed to human-made chemicals like chlorofluorocarbons (CFCs). When CFCs are released into the atmosphere, they eventually rise to the stratosphere, where they are broken down by UV radiation, releasing chlorine atoms. These chlorine atoms react with ozone (O3) molecules, breaking them down into oxygen molecules (O2) and individual oxygen atoms (O). This process depletes the ozone layer, creating 'holes' particularly over the polar regions. Depletion of the ozone layer results in more UV radiation reaching the Earth's surface, contributing to health risks and environmental issues. Therefore, protecting the ozone layer is crucial for maintaining life on Earth.