rcs said:I am confused on how to find out the heat of combustion of solid citric acid to water and carbondioxide that is deltaH 296 -1986 kJ/mol. I need to figure out the heat liberated when 10g of citric acid is totally combusted at 298k? *a) At constant pressure?? at constant volume?? and why is it not necessary to specify the pressure in part a?
The first law of thermodynamics, also known as the law of conservation of energy, states that energy cannot be created or destroyed, but can only be transferred or converted from one form to another.
The second law of thermodynamics states that the total entropy of a closed system (a system that does not exchange matter or energy with its surroundings) will never decrease over time. In other words, the natural flow of energy is from a state of order to a state of disorder.
The third law of thermodynamics states that the entropy of a perfect crystal at absolute zero temperature is zero. This means that at absolute zero, there is no disorder or randomness in the crystal, and all molecular motion ceases.
An open thermodynamic system allows both matter and energy to be exchanged with its surroundings, while a closed system only allows for the exchange of energy. This means that an open system can gain or lose mass, while a closed system cannot.
The laws of thermodynamics apply to many everyday processes, such as cooking, energy production, and transportation. For example, when cooking food, the energy from the stove is transferred to the food, causing it to increase in temperature. In energy production, the second law of thermodynamics explains why some energy is always lost in the form of heat during the transformation of one form of energy to another. In transportation, the first law of thermodynamics explains why a car needs to constantly refuel, as energy is continuously being converted from fuel to motion and lost in the form of heat.