Question

Which of the following gases cause pollution when present in the exhaust fumes of vehicles? (a) water vapours (b) \(\mathrm{CO}_{2}\) (c) \(\mathrm{CO}\) (d) \(\mathrm{C}_{2} \mathrm{H}_{6}\)

Short answer

(c) CO and (d) C2H6 are pollutants in vehicle exhaust.

Step-by-step solution

Identify the content of vehicle exhaust fumes

Exhaust fumes from vehicles contain several gases, including carbon dioxide ((CO_2)), carbon monoxide ((CO)), hydrocarbons such as ethane ((C_2H_6)), and water vapor.

Determine which gases are pollutants

Identify gases that cause pollution: Carbon monoxide ((CO)) is a harmful pollutant because it can bind with hemoglobin in the blood, reducing oxygen transport and potentially leading to health issues. Hydrocarbons like ethane ((C_2H_6)) can contribute to smog formation.

Evaluate the non-pollutant gases

Both water vapors and carbon dioxide ((CO_2)) are not considered pollutants in the context of vehicle exhaust. Water vapor is a natural component and (CO_2), although a greenhouse gas contributing to long-term climate change, is not directly toxic like (CO).

Conclude on the polluting gases

Conclude by identifying which gases from the list are pollutants when found in vehicle exhaust: Carbon monoxide ((CO)) and hydrocarbons such as ethane ((C_2H_6)) are the main pollutants from the provided options.

Key concepts

Carbon Monoxide Toxicity

Carbon monoxide (CO) is one of the key pollutants found in vehicle exhaust fumes. This colorless and odorless gas poses significant health risks when inhaled. CO's primary danger lies in its ability to bind with hemoglobin in the blood, which is the molecule responsible for carrying oxygen throughout the body. Once CO binds to hemoglobin, it forms carboxyhemoglobin, severely reducing the blood’s capacity to transport oxygen. This can result in symptoms like headaches, dizziness, and at high exposure levels, it can lead to unconsciousness or even be fatal.

Understanding just how CO affects the body is essential for health and safety. When someone breathes air containing high levels of CO, it can interfere with the heart, brain, and other vital organs. The reduced oxygen supply to these organs leads to a condition known as hypoxia. Even at low exposure levels sustained over time, chronic effects such as heart disease can develop. This makes regulating and monitoring CO emissions from vehicles vital to public health and safety.

Hydrocarbon Emissions

Hydrocarbons (HCs), another pollutant found in vehicle exhaust, play a significant role in environmental pollution. These compounds, including substances like ethane ( ext{C}_2 ext{H}_6 ), are composed of hydrogen and carbon atoms. While they come from both natural and human-made sources, vehicles are a significant contributor, particularly when engines do not burn fuel completely.

Hydrocarbons contribute to the formation of ground-level ozone, a primary component of smog. Ozone at ground level is not the same as the protective ozone layer found high up in the atmosphere. Instead, this ozone forms when hydrocarbons react with nitrogen oxides in the presence of sunlight. This smog can irritate the eyes, damage lungs, and exacerbate respiratory conditions such as asthma. It can also affect crops and other vegetation, leading to significant agricultural and economic impacts. Limiting hydrocarbon emissions is crucial for protecting both human health and the environment.

Pollutants in Exhaust Fumes

Vehicle exhaust fumes are composed of a complex mixture of gases and particles, several of which are recognized as pollutants. Some of the main pollutants in vehicle exhaust include carbon monoxide (CO) and hydrocarbons (HCs) like ethane ( ext{C}_2 ext{H}_6 ). These pollutants have adverse effects on both the environment and human health.

In addition to CO and hydrocarbons, other components in vehicle exhaust can also contribute to pollution. Substances like nitrogen oxides (NOx) and particulate matter are some examples. These pollutants can lead to environmental issues such as acid rain and contribute to respiratory problems in humans. Managing vehicle emissions involves using technologies such as catalytic converters, which help reduce the amount of harmful emissions released into the atmosphere.

Understanding the composition of vehicle exhaust and its effects can help in forming strategies to minimize environmental pollution. Transitioning to cleaner fuels and adopting electric vehicles are some measures that can further reduce the levels of harmful pollutants, leading to a healthier environment.