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Why is the enthalpy of sublimation is equal to the sum of enthalpy of fusion and enthalpy of vaporization?
Enthalpy is a state function, and to a first approximation does not depend on temperature. So the change in enthalpy to go from solid to a gas directly (sublimation) at some temperature is equal to the sum of the enthalpies associated with going from a solid to a liquid (fusion) and going from a liquid to a gas (vaporization) at other temperatures.
What else can I help you with?
What is the enthalpy change for the reverse reaction?
The enthalpy change for the reverse reaction is equal in magnitude but opposite in sign to the enthalpy change for the forward reaction.
When does heat equal enthalpy in a chemical reaction?
Heat equals enthalpy in a chemical reaction when the reaction is carried out at constant pressure.
The molar enthalpy of vaporization of benzene at its boiling point 353.25 K is 30.8 kJ mol-1 What is the molar internal energy change?
The molar internal energy change can be calculated using the equation: ΔU = ΔH - PΔV, where PΔV is the work done during the phase change. For vaporization, at constant pressure, the work done is approximately zero, so the molar internal energy change is approximately equal to the molar enthalpy of vaporization. Therefore, the molar internal energy change in this case is 30.8 kJ mol-1.
When does the change in enthalpy equal heat in a chemical reaction?
The change in enthalpy equals the heat in a chemical reaction when the reaction occurs at constant pressure.
What is the difference of enthalpy of formation and the enthalpy of combustion?
Enthalpy of combusion is energy change when reacting with oxygen. Enthalpy of formation is energy change when forming a compound. But some enthalpies can be equal.ex-Combusion of H2 and formation of H2O is equal
True or false The molar enthalpy values and fusion stay the same if you were to reverse the process?
True. The molar enthalpy values for fusion (also known as the enthalpy of fusion) are independent of the direction of the process. This means that the enthalpy change for melting a substance is equal in magnitude, but opposite in sign, to the enthalpy change for freezing the substance.
How do I convert the enthalpy of vaporization of water in joules per gram from kiloJoules per mole?
Lets say, for example the enthalpy is equal to 1200 joules/gram. You take 1200 joules/gram * (# of grams)/one mole [now you can cancel grams and it is now joules/mole.] Then convert the answer to kilojoules by dividing by 1000.
What is wrong with this statement, "As a substance freezes, it absorbs energy equal to its enthalpy of fusion"?
There is nothing inherently wrong with the statement "As a substance freezes, it absorbs energy equal to its enthalpy of fusion." In fact, this statement is a well-established scientific principle known as the Enthalpy of Fusion. When a substance changes from a liquid phase to a solid phase (freezing), it undergoes a phase change that requires a specific amount of energy to overcome the intermolecular forces holding the substance together. This energy absorbed is known as the Enthalpy of Fusion, and it is dependent on the substance and specific conditions. Therefore, this statement accurately describes the process of freezing and provides important information about how substances behave during phase changes.
What is the enthalpy change for the reverse reaction?
The enthalpy change for the reverse reaction is equal in magnitude but opposite in sign to the enthalpy change for the forward reaction.
Why doesn't the temperature of water continually increase as it heated?
Temperature doesn't give the whole picture when you talk about boiling. A more useful property to talk about is enthalpy. Enthalpy is the energy held by the water. Prior to the boiling point, enthalpy and temperature both rise linearly. At the boiling point, temperature stops rising, but enthalpy continues to rise until it becomes steam. If you were to continue adding energy to the steam, it's temperature would rise again. The amount of energy that must be added to water to get it from water just at the boiling point to steam is the latent heat of vaporization and is equal to the enthalpy rise discussed in the previous paragraph. The latent heat of vaporization and the temperature where boiling will occur are dependant on the pressure.
When does heat equal enthalpy in a chemical reaction?
Heat equals enthalpy in a chemical reaction when the reaction is carried out at constant pressure.
The molar enthalpy of vaporization of benzene at its boiling point 353.25 K is 30.8 kJ mol-1 What is the molar internal energy change?
The molar internal energy change can be calculated using the equation: ΔU = ΔH - PΔV, where PΔV is the work done during the phase change. For vaporization, at constant pressure, the work done is approximately zero, so the molar internal energy change is approximately equal to the molar enthalpy of vaporization. Therefore, the molar internal energy change in this case is 30.8 kJ mol-1.
When does the change in enthalpy equal heat in a chemical reaction?
The change in enthalpy equals the heat in a chemical reaction when the reaction occurs at constant pressure.
What is the difference of enthalpy of formation and the enthalpy of combustion?
Enthalpy of combusion is energy change when reacting with oxygen. Enthalpy of formation is energy change when forming a compound. But some enthalpies can be equal.ex-Combusion of H2 and formation of H2O is equal
Is the ionization enthalpy of the first two elements of isotopes same?
Ionization enthalpy of isotopes should be theoretically the same.But the recorded values aren't equal..nobody knows why..
What Substance Require The Most Heat To Melt 1 Kg Of The Substance?
Carbon: 105 kJ/mol = 105 (kJ/mol) / 0.012(kg/mol) = 8750 kJ/kg Carbon
Calculate w and delta E when one mole of a liquid is vaporized at its boiling point?
Delta E = q + w w = -PdeltaV Remember the Ideal Gas Law PV = nRT Depending on what is constant solve. If T and P are constant w = -PdeltaV = -P(deltan X RT/P) = -deltanRT R = 8.3145 JK-1mol-1 n = mol T = Temp in K
