Which of the following is a common chemical test for water quality?

Lead and arsenic testing is a common chemical test for water quality because it specifically evaluates the presence of heavy metals that can pose significant health risks. These substances are often found in contaminated water sources and can result from industrial pollution, mining, or the corrosion of old plumbing systems. The testing of lead and arsenic is crucial for ensuring safe drinking water, as even small amounts can have serious health effects, particularly in vulnerable populations such as children and pregnant women.

In contrast, measuring temperature is an important physical indicator of water quality but does not directly assess its chemical composition. Assessing color might provide some insight into certain contaminants or organic material, but it is not a comprehensive chemical analysis. Therefore, while temperature and color measurement are useful for understanding water conditions, they do not constitute common chemical testing for specific harmful substances as lead and arsenic testing does.