Gaurav Kumar completed a school project on checking contamination in water samples. The project involved measuring the boiling points of different water samples to determine contamination levels. Higher boiling points indicate more impurities are present in the water. Gaurav tested samples of groundwater, salt water, sand water, contaminated water, and drinking water. He found that salt water had the highest boiling point, indicating the highest level of impurities, while drinking water had the lowest boiling point. By measuring changes in boiling points, the project was able to check for contamination in water.