Is a phase change from liquid to gas endothermic or exothermic?

Asked By: Ramdane Lindow | Last Updated: 8th May, 2020
Category: science chemistry
4.6/5 (686 Views . 37 Votes)
Phases and Phase Transitions
Phase Transition Direction of ΔH
Vaporization (liquid to gas) ΔH>0; enthalpy increases (endothermic process)
Sublimation (solid to gas) ΔH>0; enthalpy increases (endothermic process)
Freezing (liquid to solid) ΔH<0; enthalpy decreases (exothermic process)

Click to see full answer


Herein, why is solid to liquid endothermic?

This means that as you move from solid to liquid to gas, all accompanying phase changes require the input of heat. Thus, these phase changes are an example of an endothermic reaction. The release of energy is felt as heat as the water vapor goes to water.

Additionally, which change is exothermic? Fusion, vaporization, and sublimation are endothermic processes, whereas freezing, condensation, and deposition are exothermic processes. Changes of state are examples of phase changes, or phase transitions. All phase changes are accompanied by changes in the energy of a system.

Accordingly, which change of phase is endothermic?

Answer and Explanation: Melting, sublimation and boiling are all phase changes which are endothermic.

Is changing from a liquid to a gas exothermic?

Thus any transition from a more ordered to a less ordered state (solid to liquid, liquid to gas, or solid to gas) requires an input of energy; it is endothermic. Conversely, any transition from a less ordered to a more ordered state (liquid to solid, gas to liquid, or gas to solid) releases energy; it is exothermic.

30 Related Question Answers Found

Is Boiling Water endothermic or exothermic?

We can all appreciate that water does not spontaneously boil at room temperature; instead we must heat it. Because we must add heat, boiling water is a process that chemists call endothermic. Clearly, if some processes require heat, others must give off heat when they take place. These are known as exothermic.

What is an example of endothermic?

These examples could be written as chemical reactions, but are more generally considered to be endothermic or heat-absorbing processes: Melting ice cubes. Melting solid salts. Evaporating liquid water. Converting frost to water vapor (melting, boiling, and evaporation, in general, are endothermic processes.

Is ice melting endothermic?

A: Well, it's a little easier going the other way. Melting ice is endothermic -- you can see this by putting a thermometer in a glass of warm water, adding an ice cube, and watching the temperature go down as the ice melts. The melting process needs heat to proceed and takes it from the warm water.

What is an example of an exothermic reaction?

Examples of Exothermic Reactions
any combustion reaction. a neutralization reaction. rusting of iron (rust steel wool with vinegar) the thermite reaction. reaction between water and calcium chloride.

Is a fridge endothermic or exothermic?


Nope it is a machine that uses the principles of expansion of a liquid to a gas. This makes the refrigerator cold in side. An endothermic reaction is one than causes a temperature drop as the reaction absorbs energy from its surroundings.

Why is freezing exothermic?

Freezing, the phase transition from liquid to solid form, is an exothermic process because energy, in the form of heat, is emitted in the process. Because freezing/melting is a first-order phase transition, there is a latent heat involved in the transition.

Which physical change is endothermic?

The physical changes that are endothermic are melting, vaporization and sublimation.

Is baking a cake endothermic or exothermic?

Exothermic is when energy energy is released. Endothermic is when energy is absorbed. Baking a cake is endothermic chemical reaction. The heat helps produces bubbles in the cake that make it light and fluffy.

Is freezing ice endothermic or exothermic?

Melting ice is an endothermic process because you need to provide heat in order to allow the molecules to overpower the hydrogen bonds and start moving about again.

Why is evaporation an endothermic process?


Evaporation is endothermic because water molecules must absorb heat from the surroundings to increase their kinetic energy. One familiar example is sweat, which cools the human body as it evaporates from the skin.

Is burning a candle endothermic or exothermic?

A candle flame is an exothermic reaction because when the candle burns it gives off heat rather than taking it in which would be endothermic.

Is Melting input or output of energy?

Phase transitions involving the breaking of intermolecular attractions (i.e., fusion (melting), vaporization, and sublimation) require an input of energy to overcome the attractive forces between the particles of the substance.

Why is boiling endothermic?

Boiling water is an endothermic process, which supplies heat to the water molecules, increasing their potential energy. Once the intermolecular bonds are broken, any extra heat increases the kinetic energy of the system and the molecules of the water vapor move faster as the temperature increases.

What is phase change diagram?

Phase diagram is a graphical representation of the physical states of a substance under different conditions of temperature and pressure. As we cross the lines or curves on the phase diagram, a phase change occurs. In addition, two states of the substance coexist in equilibrium on the lines or curves.

What happens in an exothermic reaction?


An exothermic reaction occurs when the energy used to break the bonds in the reactants (the starting stuff) is less than the energy released when new bonds are made in the products (the stuff you end up with). Combustion is an example of an exothermic reaction- you can feel the heat given off if you get too close!

Can a solid turn into a gas?

The process of changing a solid into a gas is called sublimation. This is the phase transition of a substance directly from the solid to the gas phase without passing through the intermediate liquid phase.

Is sublimation endothermic?

Yes sublimation is endothermic because it requires energy to convert a solid into a gas. The atoms or molecules in a solid substance are tightly packed. Sublimation occurs because, under certain conditions of temperature and pressure, a substance may exist in both a solid, liquid and gas phase.