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 and Temperature - 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 equa..

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 ..

The flow of information in the living cells involves two mechanisms. One of them is the flow of genetic information contained in the DNA. This information, which is responsible for all cellular activities, is present in the form of a specific sequence of nucleotides an..

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..

A chemical equilibrium involves two opposing reactions. If one of them is exothermic, the other must be endothermic. If a system at equilibrium is subjected to change in temperature, the equilibrium adjusts itself to counteract the effect of the applied change..

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..

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 undesirable effect. For example, in electric circuits, the ..

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..

Action of Heat on Sulphur - 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 ..