Consider the following:1. Carbon monoxide2. Nitrogen oxide3. Ozone4. Sulphur dioxideExcess of which of the above in the environment is/are cause(s) of acid rain?1 point(a) 1, 2 and 3(b) 2 and 4 only(c) 4 only(d) 1, 3 and 4

To determine which of the given substances can cause acid rain, we need to understand their properties and effects on the environment.

1. Carbon monoxide (CO): Carbon monoxide is not directly responsible for causing acid rain. It is primarily produced from the incomplete combustion of fossil fuels and is known for its harmful effects on human health.

2. Nitrogen oxide (NOx): Nitrogen oxide is a group of gases that includes nitrogen dioxide (NO2) and nitric oxide (NO). These gases are produced from the burning of fossil fuels, particularly in vehicles and power plants. Nitrogen oxide emissions contribute to the formation of acid rain.

3. Ozone (O3): Ozone is a gas that occurs naturally in the Earth's atmosphere. It is beneficial in the upper atmosphere, where it forms the ozone layer and protects us from harmful ultraviolet (UV) radiation. However, at ground level, ozone is a pollutant and can contribute to the formation of acid rain.

4. Sulphur dioxide (SO2): Sulphur dioxide is produced from the burning of fossil fuels, particularly those containing high levels of sulphur. It is a major contributor to acid rain formation. When released into the atmosphere, sulphur dioxide reacts with oxygen and water to form sulphuric acid, a component of acid rain.

Based on this information, we can conclude that the excess of nitrogen oxide (2) and sulphur dioxide (4) in the environment are the main causes of acid rain. Therefore, the correct answer is option (b) 2 and 4 only.