Question

At which temperature does a pure substance start boiling

Answer 1

a pure substance start boiling at the temperature of hundred degree Celsius

Answer 2

For water, the vapour pressure reaches the standard atmospheric pressure of 1 atmosphere at 100°C. So the normal boiling point of water is 100°C (212°F or 373K).The boiling point of pure water increases on the addition of soluble substances such as sugar or common salt.