IGCSE C10 Chemistry Practice Test 2026 - Free Chemistry Exam Practice Questions and Study Guide

The main adverse effect of oxides of nitrogen on the environment primarily involves their role in causing acid rain and respiratory problems. Nitrogen oxides (NOx), which include nitric oxide (NO) and nitrogen dioxide (NO2), can react with water in the atmosphere to form nitric acid. When this acid falls as precipitation, it contributes to acid rain, which can harm vegetation, soil, aquatic ecosystems, and infrastructure.

In addition to their contribution to acid rain, nitrogen oxides are also significant air pollutants that can lead to respiratory issues in humans. When inhaled, these compounds can exacerbate conditions like asthma, bronchitis, and other lung diseases, posing health risks, especially in urban areas with high traffic emissions.

Other options, while they may reflect environmental concerns, do not directly capture the predominant impact of nitrogen oxides. For example, ozone depletion is more closely related to chlorofluorocarbons and certain other compounds, rather than nitrogen oxides. Climate change is primarily driven by greenhouse gases like carbon dioxide and methane, though nitrogen oxides do have some indirect effects. Finally, promoting algal blooms typically relates to nutrient pollution from phosphates and nitrates, with nitrogen compounds playing a less direct role.

Thus, the most significant