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Why enthalpy change of hydration of magnesium sulphate cannot be measured directly?
Because this kind of reaction is usually not spontaneous. Heating maybe required to provide the required activation energy. Heating on the other hand would introduce heat change and thus a higher temperature change to the system. As a result the actual temperature change caused by the reaction is hard to measure.
What else can I help you with?
Why absolute value of enthalpy of system cannot be measured?
The absolute value of enthalpy cannot be measured because enthalpy is a state function, which means its value depends on the initial and final states rather than the absolute value. Only changes in enthalpy can be measured experimentally through processes like calorimetry.
How do you calculate the enthalpy of a reaction?
To calculate the enthalpy of a reaction, you subtract the sum of the enthalpies of the reactants from the sum of the enthalpies of the products. This is known as the enthalpy change (H) of the reaction. The enthalpy values can be found in tables or measured experimentally using calorimetry.
What is dimension of enthalpy?
The correct dimensional formula of latent heat is MoL2T2.
Why you measure enthalpy in H instead of H?
The total enthalpy of a system is called "H." That stands for "total enthalpy." It is not a measure of enthalpy. Enthalpy is measured in the SI or metric system in joules (abbreviated as J) or in customary units such as British Thermal Unit (BTU) or calories (cal).
What is heat of reaction and enthalpy of reaction?
Heat of reaction and enthalpy of reaction are the same thing. Enthalpy, or the heat transfer, cannot be measured, however we can measure the CHANGE of enthalpy which is shown by a value of ∆H. This measured in kilojoules per mole of reactant. (KJ/mol)This value may be positive or negative. For endothermic reactions (which absorb heat), the ∆H value is always positive. For exothermic, where heat is released, the value is negative.
Why absolute value of enthalpy of system cannot be measured?
The absolute value of enthalpy cannot be measured because enthalpy is a state function, which means its value depends on the initial and final states rather than the absolute value. Only changes in enthalpy can be measured experimentally through processes like calorimetry.
Why can't the enthalpy change of combustion of CO2 be measured?
The enthalpy change of combustion of CO2 cannot be measured directly because CO2 is already in its most stable form. In combustion reactions, compounds react with oxygen to form more stable products, releasing heat. Since CO2 is already at the end of the combustion process and cannot be further reacted to release more heat, its enthalpy change of combustion cannot be measured directly.
Define enthalpy and how it is measured?
Enthalpy is a particular amount of heat that is produced or released at a given pressure. There are specific equations that must be used to calculate enthalpy.
How is Hess and law used to measure enthalpy of a desired reaction?
Hess's law states that the total enthalpy change for a reaction is the sum of the enthalpy changes for individual steps, regardless of the pathway taken. To measure the enthalpy of a desired reaction, one can manipulate known reactions with known enthalpy changes to create a series of steps that lead to the desired reaction. By adding or subtracting these enthalpy changes accordingly, the overall enthalpy change for the desired reaction can be calculated. This method is particularly useful when the desired reaction cannot be measured directly.
Why does Hess's law allow you to determine the enthalpy change of a reaction?
Hess's law states that the total enthalpy change for a chemical reaction is the sum of the enthalpy changes for each individual step of the reaction, regardless of the pathway taken. This allows us to determine the enthalpy change of a reaction by adding the enthalpy changes of multiple known reactions that, when combined, yield the desired overall reaction. By using this principle, we can calculate enthalpy changes even when the reaction cannot be measured directly. Thus, Hess's law provides a systematic way to obtain enthalpy values from existing data.
How do you calculate the enthalpy of a reaction?
To calculate the enthalpy of a reaction, you subtract the sum of the enthalpies of the reactants from the sum of the enthalpies of the products. This is known as the enthalpy change (H) of the reaction. The enthalpy values can be found in tables or measured experimentally using calorimetry.
What is hess's law used to measure enthalpy of a desired reaction?
Hess's Law states that the total enthalpy change for a chemical reaction is the same, regardless of the pathway taken, provided the initial and final states are the same. This principle allows for the calculation of the enthalpy change of a desired reaction by using the enthalpy changes of multiple intermediate reactions that add up to the overall reaction. By summing these known enthalpy changes, one can derive the enthalpy of the target reaction, even if it cannot be measured directly. This makes Hess's Law a valuable tool in thermochemistry for determining reaction enthalpies.
What is dimension of enthalpy?
The correct dimensional formula of latent heat is MoL2T2.
Is qrxn delta h of reaction under the same pressure?
Yes, ( q_{rxn} ) (the heat of reaction) is equal to the change in enthalpy (( \Delta H )) of the reaction when measured at constant pressure. This is because, under constant pressure conditions, the heat exchanged in a reaction corresponds directly to the change in enthalpy. Thus, ( q_{rxn} = \Delta H ) at constant pressure.
How many liters of oxygen are needed to produce 40 L magnesium oxide?
Magnesium oxide is a solid, not measured in litres.
Why you measure enthalpy in H instead of H?
The total enthalpy of a system is called "H." That stands for "total enthalpy." It is not a measure of enthalpy. Enthalpy is measured in the SI or metric system in joules (abbreviated as J) or in customary units such as British Thermal Unit (BTU) or calories (cal).
What is the relationship between enthalpy of atomisation of hydrogen and the bond dissociation enthalpy of the H-H bond?
the enthalpy of atomisation of hydrogen is equal and (in principle) identical to the bond dissociation enthalpy of the H-H bond. However, IF the first is measured by calorimetry and the second by spectrometry there might be a systematic difference.
