Effect of Change of Temperature

Temperature is the measurement of heat of a system or substance. In most chemical reactions, the rate of an enzyme-catalysed reaction increases as the temperature is raised. Temperature is the internal energy contained within a particular system. Temperature can be measured by a thermometer. Celsius is the unit for measuring temperature, which is denoted by °C. Kelvin is also the unit of temperature. Temperature changes the states of matter into each other by decreasing or increasing. Temperature melts solid into a liquid state and this process is called melting or fusion.

Temperature Effect/Effect of Temperature

Temperature affects matter, reactions and enzymes in many different ways. The state of a substance can be changed by increasing or decreasing temperature. Solid can be converted to liquid on increasing temperatures and liquid can be converted to gas at high temperatures. Solid can be directly converted to gas at high temperatures. This process is called sublimation. Similarly, gases can be converted into liquids by decreasing temperature and increasing pressure and liquid can be converted into solids at low temperatures. Temperature also affects the rate of reaction in a positive or negative way.

The Effect of Change of Temperature on Solid State

The kinetic energy of the particles increases with increasing temperature. This increase in kinetic energy increases the speed of particles and the particles start vibrating with greater speed. The energy supplied by heat decreases or overcomes the forces of attraction between the particles. The particles remove from their fixed positions and start moving more freely. At a stage, the solid melts and is converted to liquid. The temperature at which solid melts to become a liquid is called its melting point. This process is called fusion when two separate solid objects made from the same substance are melted, they can get mixed together into a new one.

Effect of Change of Temperature on States of Matter

The main ways to change matter from one state to another are heating and cooling. We can convert a solid into a liquid by giving it heat. Similarly, liquid can be changed to gas by heating. The reverse is also true, when gas is removed, some of its heat energy becomes liquid. When a liquid is further removed, its heat energy becomes solid.

The kinetic energy of particles and inter-space between them increases due to the increasing temperature. This increase in kinetic energy and space between the particles decreases the force of attraction between particles.

Effect of Temperature on Pressure

Pressure is a physical force applied on an object by something in contact with it. Pressure is calculated as the force per unit area. The pressure exerted by the gas (which is enclosed in a chamber surrounded by a vacuum) on the walls of the chamber depends on three factors: the amount of gas in the chamber, the volume of the chamber and the temperature of the gas.

With respect to gases, the relationship between pressure and temperature is described. The pressure-temperature relationship is described by gas law which states that the pressure of a given amount of a particular gas is directly proportional to its temperature at a constant volume. It can be represented as:

\[P\alpha T\]

When the temperature of a particular system is increased, the speed of molecules in the gas becomes faster, exerting greater pressure on the wall of the gas container. Due to this, the pressure on the system increases. If the temperature of the system is decreased, the pressure also decreases. Therefore, the pressure of a particular gas is directly proportional to the temperature at constant volume.

When the temperature increases, the volume of the gas also increases at constant pressure. As the temperature increases, the kinetic energy of the molecule increases and the gas needs more volume to move that is why volume increases.

Examples of Effect of Temperature

One example of the effect of temperature on chemical reaction rates is the use of light sticks or glow sticks. The light stick undergoes a chemical reaction that is called chemiluminescence. But this reaction does not require or produce heat. Its rate is affected by temperature. Other examples are precipitation reaction, activation energy etc.

Interesting Facts

• Solids can be converted into gases directly at high temperatures, which is called sublimation.

• Temperature affects the reactivity of an enzyme catalyst.

• The rate of reaction changes on decreasing or increasing temperature.

Key Features

• Temperature can change the kinetic energy of particles of a substance. At high temperatures, the kinetic energy of particles is very fast and at low-temperature particles move slowly.

• High temperature converts solids into liquids and liquids into gases.

• Low temperature converts gases into liquids and liquids into solids.

• Pressure is also increased with increasing temperature.

Summary

There is so much effect of temperature on the difference of the states of matter. The temperature affects different states of matter. As the temperature increases, the kinetic energy of the state increases but the force of attraction is different in every state. There is also an effect on the different states of matter at constant volume and constant pressure. As the volume is constant, the pressure of the gas decreases. When the pressure is constant, the volume of the gas increases.