The formula for potential energy depends on the force acting on the two objects. For the gravitational force the formula is P.E. = mgh, where m is the mass in kilograms, g is the acceleration due to gravity (9.8 m / s2 at the surface of the earth) and h is the height in meters.

Gravitational potential energy is the energy stored in an object as the result of its vertical position or height. The energy is stored as the result of the gravitational attraction of the Earth for the object.

Potential energy is energy that is stored in an object or substance. Gravitational potential energy is energy in an object that is held in a vertical position.

Examples of Gravitational Potential Energy

• A raised weight.
• Water that is behind a dam.
• A car that is parked at the top of a hill.
• A yoyo before it is released.
• River water at the top of a waterfall.
• A book on a table before it falls.
• A child at the top of a slide.
• Ripe fruit before it falls.

An energy barrier is a potential field that can be used to either localize or regulate the transfer of charged particles, for example, electrons. In one case, if the potential field defining the barrier is not high enough, thermally activated electrons can escape over the barrier. Explanation: Hope it Helps.

An enthalpy diagram plots information about a chemical reaction such as the starting energy level, how much energy needs to be added to activate the reaction, and the ending energy. An enthalpy diagram is graphed with the enthalpy on the y-axis and the time, or reaction progress, on the x-axis.

Endothermic reactions are the opposite of exothermic reactions. They absorb heat energy from their surroundings. This means that the surroundings of endothermic reactions are colder as a result of the reaction. Melting ice is an example of this type of reaction.

When an ice cube tray, filled with water is placed in a freezer, it slowly loses heat and start to cool down to become ice cubes. Changing of water into an ice cube is an exothermic reaction. Snow formation in clouds is also an exothermic reaction. Clouds come into existence from condensation of water vapor.

In this case of cooking an egg,the system(egg) gets heated up and for this the energy is taken from the environment(pan). So the reaction is an endothermic reaction. An exothermic reaction can be as simple as burning wood.

Instant cold packs use chemical reaction. Are these reactions endothermic or exothermic? Cold packs are endothermic because they take heat from their surroundings.

A burning candle is an example of an exothermic reaction.

When water becomes a solid, it releases heat, warming up its surroundings. This makes freezing an exothermic reaction. Usually, this heat is able to escape into the environment, but when a supercooled water bottle freezes, the bottle holds much of that heat inside.

When heat is absorbed by the solution, q for the solution has a positive value. When heat is absorbed from the solution q for the solution has a negative value. This means that the reaction absorbs heat fron the solution, the reaction is endothermic, and q for the reaction is positive.

An endothermic process is any process with an increase in the enthalpy H (or internal energy U) of the system. In such a process, a closed system usually absorbs thermal energy from its surroundings, which is heat transfer into the system.

When enthalpy is negative and delta H is less than zero, this means that a system released heat. This is called an exothermic reaction. For example, when water changes from liquid to gas, delta H is positive; the water gains heat. When water changes from liquid to solid, delta H is negative; the water loses heat.

If more energy is released in making bonds than is used in breaking bonds, the overall process is exothermic, and ∆Hsol is negative. If more energy is used in breaking bonds than is released upon solute-solvent bond formation, then the overall process is endothermic, and ∆Hsol is positive.

A system that releases heat to the surroundings, an exothermic reaction, has a negative ΔH by convention, because the enthalpy of the products is lower than the enthalpy of the reactants of the system. The enthalpies of these reactions are less than zero, and are therefore exothermic reactions.

exothermic

Enthalpy change

Gibbs free energy relates enthalpy, entropy and temperature. A spontaneous reaction will always occur when Delta H is negative and Delta S is positive, and a reaction will always be non-spontaneous when Delta H is positive and Delta S is negative.

The entropy of the system increases with its size according to, *In a reversible process the total entropy of a system plus its surrounding is unchanged. delta Suniv = 0. *In a irreversible process the total entropy of a system plus its surrounding increase.