The reason for the different behaviors observed when putting room temperature water and 99% isopropyl alcohol in hot quartz is due to their different thermal expansion properties and boiling points.
Quartz is a crystalline material that exhibits a relatively low coefficient of thermal expansion, meaning it does not expand significantly when exposed to heat. When room temperature water is suddenly poured into hot quartz, the temperature difference between the water and the quartz causes rapid and uneven thermal expansion. The uneven expansion creates stress within the quartz, and if the stress exceeds the quartz's strength, it can lead to the material shattering or breaking.
On the other hand, isopropyl alcohol has a much lower boiling point compared to water. When you pour room temperature 99% isopropyl alcohol into hot quartz, the alcohol quickly absorbs the heat and reaches its boiling point, which is around 82 degrees Celsius (180 degrees Fahrenheit) for 99% concentration. As a result, the alcohol rapidly vaporizes and evaporates, turning into a gas without exerting excessive stress on the quartz.
In summary, the differential thermal expansion between the hot quartz and room temperature water, combined with the higher boiling point of water, can cause stress and lead to the shattering or breaking of the quartz. In contrast, isopropyl alcohol evaporates at a much lower temperature, avoiding the same stress-induced breakage.