Question

boiling point (fixed temperature or temperature different in different times..​

Answer 1

Boiling point is always in fixed temperature.

For example:- The boiling point of water is 100°C.

In evaporation, the temperature varies.

Hope it is helpful for you.

THANK YOU..

Answer 2

Answer:

• The boiling point is the point a substance turns from liquid to gas.
• The boiling point for water is 100* Celsius or 212* Fahrenheit.
• The reason boiling points stay the same is molecular structure. The atoms or molecules that make up any object or substance are constantly in motion.
• The more friction between molecules, the higher it’s temperature. For example, water molecules in ice move less than water molecules in liquid form.
• When the molecules have more friction they heat up, spreading apart and allowing more friction to take place. When a substance reaches its boiling point its molecules are spread far enough apart that for its temperature to go any higher it must turn into a gas.
• Other substances can boil besides water, and each substance has a different boiling point. The boiling point is determined by how fast the molecules move at a certain temperature. Since the molecules never change, that temperature never changes.
• At the boiling point, the liquid phase of a substance is not all converted at once to the vapor phase.
• You have in fact an intermediate mixture of vapor and liquid which at all times try to be in thermal equilibrium or at the same temperature with each other.
• So unless all the liquid is boiled off, the temperature reading for the mixture will remain at the boiling point. Once no liquid is present, the vapor phase will be able to absorb energy to increase its temperature.