In order to understand the concept of heat, it is important to first understand the concept of energy. Energy is the ability to do work. Heat is a form of energy that is transferred between two objects that are at different temperatures. The transfer of heat occurs when the molecules of the two objects interact with each other. The molecules of the hotter object will transfer some of their energy to the molecules of the cooler object.
The amount of heat transferred between two objects is dependent on the difference in temperature between the two objects, as well as the properties of the objects themselves. The heat transfer equation is:
Q = δhA(t1 – t2)
Where Q is the amount of heat transferred (in Joules), δh is the heat transfer coefficient (in Watts per square meter per degree Kelvin), A is the surface area of the objects that are in contact with each other (in square meters), t1 is the temperature of the hotter object (in degrees Kelvin), and t2 is the temperature of the cooler object (in degrees Kelvin).
The heat transfer coefficient, δh, is a measure of how efficiently heat is transferred between two objects. The higher the heat transfer coefficient, the more efficient the heat transfer. In general, metals have high heat transfer coefficients, while insulators have low heat transfer coefficients.
The heat transfer equation can be rearranged to solve for the heat transfer coefficient:
δh = Q/(A(t1 – t2))
As you can see, the heat transfer coefficient is directly proportional to the amount of heat that is transferred. Therefore, when energy is transferred as heat from the system to the surroundings, δh is negative.
Other related questions:
Q: When energy is transferred as heat from the system to the surroundings H is negative?
A: When energy is transferred as heat from the system to the surroundings, H is negative.
Q: Is ΔH positive or negative?
A: The answer to this question depends on the context in which it is asked. In general, ΔH is the change in enthalpy of a system, which can be either positive or negative.
Q: Is heat absorbed by surroundings positive or negative?
A: The answer to this question depends on the perspective from which you are looking at it. From the perspective of the system, heat absorbed by the surroundings is positive because it results in an increase in entropy. From the perspective of the surroundings, heat absorbed by the system is negative because it results in a decrease in entropy.
Q: What does negative delta H mean?
A: Negative delta H means that the reaction is exothermic, meaning that heat is released during the reaction.