problems involving heat flow and temperature changes

There are two types of reactions based on heat changes involved: exothermic and endothermic. Exothermic - Most of reactions we call burning are exothermic. They give out heat. This is indicated by writing '+ Heat' on the products side of an equation..

Heat energy is present in every object above absolute zero. How do we know that heat is present in every object? Temperature of the body is an indication. (Absolute zero is the lowest temperature possible and is equal to -273 o C). Are heat and ..

We have already observed that when a substance is heated, the very first effect we observe is that its temperature rises. Similarly when a substance is cooled (i.e. heat energy is removed from the substance) the temperature of a substance decreas..

Practical Applications of Joule's Heating - This heating is inevitable in any electrical circuit. Since the energy lost by the flowing charges ends up as disorderly thermal motion, the phrase 'ohmic dissipation' is also used to describe it. Often, this is an undesirabl..

The heat of formation D H f depends upon the condition of temperature, pressure and physical state (gas, liquid or solid) of the reactants and the products. Therefore the heat change accompanying the formation of one mole of a compound from its elements wh..

When heated, sulphur undergoes a series of characteristic changes. Sulphur can melt at two different temperatures. a) If heated rapidly, it melts at 112.8 o C. b) But if heated slowly it will melt only at 118.6 o C. Roll sulphur is rhombic. When ..

Enthalpy (H) and Enthalpy Change ( D H) - It has been seen that energy change occurring during the reaction at constant temperature and constant volume is given by internal energy change. However, most of the reactions in the laboratory are carried out in ope..

Heat flow and Work - Forms of energy transfer First Law of Thermodynamics Law of conservation of energy Thermal energy Distribution of energy levels in a system Entropy of a system Second Law of Thermodynamics Problems involving heat ..

Heat flow and Work - Forms of energy transfer First Law of Thermodynamics Law of conservation of energy Thermal energy Distribution of energy levels in a system Entropy of a system Second Law of Thermodynamics Problems involving heat ..

Energy exchanged between the system and the surroundings when they are at different temperatures is commonly known as heat. If a system is at a higher temperature than the surroundings, then there is a flow of heat (or energy) from system to surrou..