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How do you know if an enthalpy change diagram is endothermic or exothermic?
Wiki User
∙ 16y ago
If you plot the reaction coordinate (what I think you mean by "enthalpy change diagram"), the reaction will be exothermic if the products are lower on the graph than the reactants. If they are higher than it is endothermic. For instance, if you go to the linked Wikipedia page (link to the left of this answer), the graph shown is of an exothermic reaction.
Wiki User
∙ 16y ago
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What is the sign of ΔT in an endothermic reaction?
ΔH is the enthalpy of the reaction and will be positive in an endothermic reaction and negative in an exothermic reaction.ΔT designates a change in temperature. T2-T1 = ΔTOften the change in temperature will be negative for an endothermic reaction.
What does it mean if the change in enthalpy value for a chemical reaction is positive?
Change in enthalpy value for a chemical reaction is positive is because,there loose of electron(s) in the reaction, and that will change the enthalpy of that particular element from negetive,neutral to positive.
What is the difference of the endothermic and exothermic change?
An endothermic change requires heat, and an exothermic change releases heat.
Does the sign of the enthalpy of fusion change depending on the direction of the phase change for example the enthalpy of fusion of water is 6025 JK per mol and going from liquid to ice is -6025?
The sign only depends on whether it's an exothermic or endothermic reaction. So no, it doesn't depend on phase change, and in some reactions, there is no phase change. But you will find correlation between the sign and the direction of the phase change because they will either be endothermic or exothermic. The enthalpy of fusion is positive because melting is an endothermic reaction (think - you put in heat to melt an ice cube). Endothermic reactions are represented by positive enthalpy. Conversely, freezing is an exothermic process (heat is taken out of the molecules in order to slow them down). We represent exothermic reactions with negative enthalpy.Always be conscious of the sign when working with thermochemistry calculations. Unlike the usual math, the signs of these numbers are somewhat arbitrary. We say that the system is losing heat in an exothermic reaction; thus, the energy must be represented by a negative. However, there are a few areas (like electrical engineering) where an exothermic reaction is represented by a positive number (because usually the goal is to produce heat).
Evaporation of perspiration is an endothermic or exothermic change Why?
Evaporation is an endothermic process because absorb energy.
Is vaporisation an exothermic or endothermic process?
Any reaction categories into exothermic and endothermic based upon change in enthalpy of reaction. If difference in enthalpy of product and reactant comes positive value then it is termed as endothermic and if it is negative value then exothermic reaction. Usually, vaporisation is considered as exothermic due to release in energy.
What is the sign of ΔT in an endothermic reaction?
ΔH is the enthalpy of the reaction and will be positive in an endothermic reaction and negative in an exothermic reaction.ΔT designates a change in temperature. T2-T1 = ΔTOften the change in temperature will be negative for an endothermic reaction.
What is one similarity between exothermic reaction and an endothermic reaction?
Endothermic reactions and exothermic reactions all involve something called an enthalpy change: a change in the amount of energy a chemical contains. The difference here is that exothermic reactions release heat energy to their surroundings, whereas endothermic reactions absorb heat from their surroundings (in effect, getting colder).
Is freezing an endothermic change or a exothermic change?
It is an exothermic change
Compare endothermic and exothermic?
An endothermic change requires heat, and an exothermic change releases heat.
What does it mean if the change in enthalpy value for a chemical reaction is positive?
Change in enthalpy value for a chemical reaction is positive is because,there loose of electron(s) in the reaction, and that will change the enthalpy of that particular element from negetive,neutral to positive.
Is a candle a endothermic or exothermic change?
exothermic- because exothermic gives off heat and endothermic is cold
What is the difference of the endothermic and exothermic change?
An endothermic change requires heat, and an exothermic change releases heat.
What is the sign of the enthalpy change for an endothermic reaction?
Endothermic reaction: In an endothermic reaction, the products are higher in energy than the reactants. Therefore, the change in enthalpy is positive, and heat is absorbed from the surroundings by the reaction therefore enthalpy change show positive sign in a endothermic reaction..
What change is the opposite of an exothermic change?
endothermic change
Is solid exothermic or endothermic?
A solid is itself neither endothermic or exothermic. However the phase change from liquid to solid will likely be exothermic.
Is butter melted in a pan a endothermic or exothermic change?
This is an endothermic process.
