Bond Enthalpy

Bond energy is the amount of energy released when 1 mole of bonds are formed from the isolated atoms in the gaseous state or the amount of energy required to dissociate one mole of bonds present between the atoms in the gaseous molecules. It is represented by Δ b H or Δbond H. For diatomic molecules like H2, …

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Measurement Of Change In Internal Energy and Enthalpy

The experimental technique of measuring energy changes accompanying any chemical or physical process is called calorimetry. These measurements are generally carried out under 2 condition 1)at constant volume ( ΔU or qv ) 2)at constant pressure ( ΔH or qp) Measurements of ΔU Internal energy change is measured experimentally using an apparatus called Bomb calorimeter. It consists of …

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Heat Capacity

Heat capacity of a system is defined as the amount of heat required to raise the temperature of the system through 1°C . If q is the amount of heat supplied to a system and as a result ,if the temperature of the system rises from T1 and T2 ,then the heat capacity of the …

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Enthalpy

According to first law of thermodynamics, q= ΔU + PΔV If the process is carried out at constant volume , ΔV=0 qv = ΔU where v indicates constant volume. Internal energy change is the heat absorbed or evolved at constant volume. ΔU is a state function, therefore qv ,is also a state function. If the process is …

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Internal Energy

Internal Energy Whenever some process occur ,it is usually accompanied by some energy change. The energy may appear in different forms such as heat ,light ,work. The evolution or absorption of energy in different processes shows that every substance must be associated with some definite amount of energy ,the actual value of which depends upon …

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