PHY12L E302 - ANALYSIS Temperature is quantity that...

• Test Prep
• 11
• 100% (2) 2 out of 2 people found this document helpful

This preview shows page 1 - 4 out of 11 pages.

ANALYSIS Temperature is quantity that measures hotness or coldness of a material. Most of the time, we denote heat as temperature or temperature equivalent to heat. But the right thing to say is that the change in temperature causes transmission of heat. It does not conclude that a cold material shares its coolness to a hotter material but the hotter material transfer its heat to such colder body to attain the so called thermal equilibrium. Practical Example of Thermal equilibrium is when you want to make ice. When you place water in a container inside the freezer, at some point of time the water changes phase from liquid to solid and acquires the shape of the container and its temperature drops to the freezing point of temperature. It is because both of the system (the water and the freezer) finds balance with their temperatures. The freezer gains heat and the water losses heat until both systems are in thermal equilibrium. Heat can only be identified as it is being transferred from one system to another. Heat transfer is a path function (process quantity), as opposed to a point function (state quantity). Heat flows between systems that are not in thermal equilibrium with each other; it spontaneously flows from the areas of high
temperature to areas of low temperature. All systems (matter) have a certain amount of internal energy. Internal energy is a property that is a measure of all microscopic ways by which a system can possess energy, for example the random motion of its atoms or molecules. When two bodies of different temperature come into thermal contact, they will exchange internal energy until their temperatures are equalized; that is, until they reach thermal equilibrium. The amount of heat transferred is equal to the amount of energy exchanged between the two bodies. It is a common misconception to confuse heat with internal energy. A hot object doesn’t contain heat it contains internal energy. The adjective hot is used as a relative term to compare the object’s temperature to that of the surroundings (or that of the person using the term). The term heat is used to describe the flow of energy. In the absence of work interactions, the heat that is transferred to an object ends up getting stored in the object in form internal energy. Calorimetry is the science or act of measuring changes in parameters of chemical reactions , physical changes and phase transitions , for the purpose of deriving the heat or heat transfer associated with those changes. Calorimetry is performed with a calorimeter . The word calorimetry is derived from the Latin word calor, meaning heat and the Greek word μέτρον (metron), meaning measure. Scottish physician and scientist Joseph Black , who was the first to recognize the
distinction between heat and temperature is said to be the founder of the science of calorimetry.