Chemistry Regents Practice Test 2025 – The All-in-One Guide to Exam Success!

The boiling point of water at standard atmospheric pressure, defined as 1 atmosphere (or 101.3 kPa), is 100 degrees Celsius. This temperature is significant because it represents the point at which the vapor pressure of the water equals atmospheric pressure, allowing bubbles of vapor to form within the liquid.

At temperatures below this, water exists in a liquid state, and as the temperature increases towards 100 degrees Celsius, the molecules gain energy and begin to escape into the air as gas (steam). Understanding the boiling point of water is essential in various scientific and practical applications, such as cooking, chemical reactions, and environmental science.

The other temperature options provided do not represent the boiling point of water under standard conditions. 50 degrees Celsius and 75 degrees Celsius are well below the boiling point, while 120 degrees Celsius exceeds the boiling point, which could occur in a pressurized system but not under normal atmospheric pressure.