Changes of state are physical changes. They occur when matter absorbs or loses energy. Processes in which matter changes between liquid and solid states are freezing and melting. Processes in which matter changes between liquid and gaseous states are vaporization, evaporation, and condensation.

All of the diagonal line segments on a heating or cooling curve show a temperature change and therefore a change in kinetic energy. However, all the energy that is absorbed or released is related to changes in potential energy. Remember the 3 Ps: Plateau, Phase change and Potential Energy Change.

The temperature remains constant during the change of state because the heat energy which is supplied to change the state of matter is used in breaking the intermolecular forces and other attractive forces. Hence the temperature remains constant as all the heat is used up and no external heat is released or absorbed.

Answer: (1) List of state functions is pressure, temperature, volume, mass, internal energy, Gibb’s free energy, entropy.

A state function is a property whose value does not depend on the path taken to reach a specific value. For the sake of this class, pressure, density, temperature, volume, enthalpy, internal energy, Gibb’s free energy, and entropy are state functions.

Heat and work are not state functions. Work can’t be a state function because it is proportional to the distance an object is moved, which depends on the path used to go from the initial to the final state.

This means internal energy is a state function (as it is independent of the path). Enthalpy is the sum of internal energy and product of pressure and volume of the thermodynamic system. This means enthalpy is a state function. Entropy is defined as thermal energy per unit temperature that is available for doing work.

A state function is a property describes a particular state, without depending on the path taken to reach this state. In contrast, functions whose value depends on the path taken to get between two states are called path functions.

Temperature is a state function as it is one of the values used to define the state of an object. Furthermore, temperature is dependent on the final and initial values, not on the path taken to establish the values. As a result, volume is a state function because it is not dependent on the object’s path or history.

Temperature is a state function. Heat and work are not state functions. Work can’t be a state function because it is proportional to the distance an object is moved, which depends on the path used to go from the initial to the final state. If work isn’t a state function, then heat can’t be a state function either.

The change in internal energy during a process depends only upon the initial state and final state while work depends on upon the path followed. Thus, internal energy is a state function and work is not.

The Internal Energy, U, of a system is an extensive thermodynamic property that measures the energy stored in a system as a result of its microscopic structure. Both of these energy transfer processes are path dependent, however, the internal energy is a function only of the state of the system.

Internal energy, in thermodynamics, the property or state function that defines the energy of a substance in the absence of effects due to capillarity and external electric, magnetic, and other fields.

Substances can change phase—often because of a temperature change. At low temperatures, most substances are solid; as the temperature increases, they become liquid; at higher temperatures still, they become gaseous. The process of a solid becoming a liquid is called melting.

During a phase change, the temperature of the system does not change, because the added heat is melting the solid at its melting point or evaporating the liquid at its boiling point.

Evaporation is increased by higher temperatures, a greater surface area or a draft over this surface area. A substance must absorb heat energy so that it can melt or boil. The temperature of the substance does not change during melting, boiling or freezing – even though energy is still being transferred.

Changes of state are physical changes in matter. They are reversible changes that do not involve changes in matter’s chemical makeup or chemical properties. Common changes of state include melting, freezing, sublimation, deposition, condensation, and vaporization. These changes are shown in Figure below.

Physical conditions like temperature and pressure affect state of matter. When thermal energy is added to a substance, its temperature increases, which can change its state from solid to liquid (melting), liquid to gas (vaporization), or solid to gas (sublimation).

As temperatures increase, additional heat energy is applied to the constituent parts of a solid, which causes additional molecular motion. Molecules begin to push against one another and the overall volume of a substance increases. At this point, the matter has entered the liquid state.

Matter changes state when energy is added or taken away. Most matter changes because of heat energy. When matter is heated enough, the molecules move faster and with greater energy. If enough heat is added, a solid can become liquid and a liquid can become gas.

Adding or removing energy from matter causes a physical change as matter moves from one state to another. For example, adding thermal energy (heat) to liquid water causes it to become steam or vapor (a gas). Physical changes can also be caused by motion and pressure.

All matter exists as solids, liquids, or gases. Matter can change from one state to another if heated or cooled. If ice (a solid) is heated it changes to water (a liquid). This change is called MELTING.

When a substance is heated, it gains thermal energy. Therefore, its particles move faster and its temperature rises. When a substance is cooled, it loses thermal energy, which causes its particles to move more slowly and its temperature to drop.

When a solid is heated, the particles gain sufficient energy to break away from one another and move past each other. The change from solid to liquid is called melting or fusion.

A change of state is a physical change in a matter. They are reversible changes and do not involve any changes in the chemical makeup of the matter. Common changes of the state include melting, freezing, sublimation, deposition, condensation, and vaporization.

Change in state of matter is a physical change because of the physical condition and appearance changes but not the chemical composition.

Explanation: Atoms lose energy as a gas changes to a solid. Atoms gain energy as a solid changes to a liquid. If atoms energy during a change of state, they are pulled together by attractive forces and become more organized.

change of state is defined as the physical process where matter moves from one state to another. Evaporation changes the form of water from liquid state to gaseous state. Usually in order to change the state of liquids into a solid state, one reduces the temperature.

The changes of state include melting, sublimation, evaporation, freezing, condensation, and deposition. All changes of state involve the transfer of energy. The water particles in each state behave as energy is absorbed or released. .

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.

When a solid reaches the temperature of its melting point, it can become a liquid. For water, the temperature needs to be a little over zero degrees Celsius (0oC) for you to melt. If you were salt, sugar, or rock, your melting point is higher than that of water.

State the law of conservation of mass and the law of conservation of energy and explain how they apply to changes of state. Mass cannot be created or destroyed. Energy cannot be created or destroyed. During a change of state, The total mass and the total energy of the system remain constant.

Conservation of mass The number of particles does not change during a change of state, only their spacing and arrangement. As a result, the total mass has not changed. It does not matter if a substance melts, freezes, boils, evaporates, condenses or sublimates – the mass does not change.