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How is the enthalpy of reaction related to the enthalpies of formation for the products and reactants?
Wiki User
∙ 9y ago
The difference between the enthalpy of formation of the products minus the enthalpy of formation of the reactants is the enthalpy of the reaction
Wiki User
∙ 9y ago
UnKnowN
Wiki User
∙ 11y agoReactants is what you began with in the chemical reaction.
Products are what you end up with at the end (result)
reaction - left side of equation
product - right side of equation
Wiki User
∙ 12y agoType your answer here...
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∙ 12y agochoclate milk and carrots
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What is the basic difference between enthalpy of formation?
Standard Heat (Enthalpy) of Formation, Hfo, of any compound is the enthalpy change of the reaction by which it is formed from its elements, reactants and products all being in a given standard state.By definition, the standard enthalpy (heat) of formation of an element in its standard state is zero, Hfo = 0.Standard Molar Enthalpy (Heat) of Formation, Hmo, of a compound is the enthalpy change that occurs when one mole of the compound in its standard state is formed from its elements in their standard states.Standard Enthalpy (Heat) of Reaction, Ho, is the difference between the standard enthalpies (heats) of formation of the products and the reactants.Ho(reaction) = the sum of the enthalpy (heat) of formation of products - the sum of the enthalpy (heat) of formation of reactants: Ho(reaction) = Hof(products) - Hof(reactants)To calculate an Enthalpy (Heat) of Reaction:Write the balanced chemical equation for the reaction Remember to include the state (solid, liquid, gas, or aqueous) for each reactant and product.Write the general equation for calculating the enthalpy (heat) of reaction: Ho(reaction) = Hof(products) - Hof(reactants)Substitute the values for the enthalpy (heat) of formation of each product and reactant into the equation. Remember, if there are 2 moles of a reactant or product, you will need to multiply the enthalpy term by 2, if molar enthalpies (heats) of formation are used.Standard Enthalpy (Heat) of FormationExample: Standard Enthalpy (Heat) of Formation of WaterThe standard enthalpy (heat) of formation for liquid water at 298K (25o) is -286 kJ mol-1. This means that 286 kJ of energy is released when liquid water, H2O(l), is produced from its elements, hydrogen and oxygen, in their standard states, ie, H2(g) and O2(g).This reaction is written as:H2(g) + ½O2(g) -----> H2O(l) Hfo = -286 kJ mol-1The standard enthalpy (heat) of formation of water vapour at 298K (25o) is -242 kJ mol-1.This means that 242 kJ of energy is released when gaseous water (water vapour), H2O(g), is produced from its elements, hydrogen and oxygen, in their standard states, ie, H2(g) and O2(g).This reaction is written as:H2(g) + ½O2(g) -----> H2O(g) Hfo = -242 kJ mol-1
Which occurs faster at equilibrium the formation of products from reactants or reactants from the product?
At equilibrium, the formation of products from reactants will be faster.
In an exothermic reaction is the energy of the products higher or lower than that of the reactants?
In an exothermic reaction the energy of the products is less than that of the reactants.
What is H in the equation G H TS?
The change in entropy between products and reactants in a reaction
Would this reaction happen NaCl plus CaF2 - NaF plus CaCl2?
The reaction is2NaCl + CaF2 --> 2NaF + CaCl2and the enthalpies of formation (kJ/Mol) of the solids at STP are2NaCl = (-411)*2CaF2 = -1220Total = -20422NaF = (-469)*2CaCl2 = -796Total = -1734The calculations show that the reactants are more stable than the products by some 307kJ/mol, so that the reaction would not proceed. (For more advanced readers, the value for the Gibbs free energy of formation will not be very much different from this, as the entropy terms will be relatively small in comparison with the enthalpy terms.) A major factor in this is the relatively high lattice enthalpy of CaF2.
What is the basic difference between enthalpy of formation?
Standard Heat (Enthalpy) of Formation, Hfo, of any compound is the enthalpy change of the reaction by which it is formed from its elements, reactants and products all being in a given standard state.By definition, the standard enthalpy (heat) of formation of an element in its standard state is zero, Hfo = 0.Standard Molar Enthalpy (Heat) of Formation, Hmo, of a compound is the enthalpy change that occurs when one mole of the compound in its standard state is formed from its elements in their standard states.Standard Enthalpy (Heat) of Reaction, Ho, is the difference between the standard enthalpies (heats) of formation of the products and the reactants.Ho(reaction) = the sum of the enthalpy (heat) of formation of products - the sum of the enthalpy (heat) of formation of reactants: Ho(reaction) = Hof(products) - Hof(reactants)To calculate an Enthalpy (Heat) of Reaction:Write the balanced chemical equation for the reaction Remember to include the state (solid, liquid, gas, or aqueous) for each reactant and product.Write the general equation for calculating the enthalpy (heat) of reaction: Ho(reaction) = Hof(products) - Hof(reactants)Substitute the values for the enthalpy (heat) of formation of each product and reactant into the equation. Remember, if there are 2 moles of a reactant or product, you will need to multiply the enthalpy term by 2, if molar enthalpies (heats) of formation are used.Standard Enthalpy (Heat) of FormationExample: Standard Enthalpy (Heat) of Formation of WaterThe standard enthalpy (heat) of formation for liquid water at 298K (25o) is -286 kJ mol-1. This means that 286 kJ of energy is released when liquid water, H2O(l), is produced from its elements, hydrogen and oxygen, in their standard states, ie, H2(g) and O2(g).This reaction is written as:H2(g) + ½O2(g) -----> H2O(l) Hfo = -286 kJ mol-1The standard enthalpy (heat) of formation of water vapour at 298K (25o) is -242 kJ mol-1.This means that 242 kJ of energy is released when gaseous water (water vapour), H2O(g), is produced from its elements, hydrogen and oxygen, in their standard states, ie, H2(g) and O2(g).This reaction is written as:H2(g) + ½O2(g) -----> H2O(g) Hfo = -242 kJ mol-1
How do you solve Hess's law problems?
write out the balanced equation that you need then write out formation equations (2-4) that will give you those reactants and products. manipulate the equations by reversing them or multiplying or dividing by whatever number. until you have what you need for the original equation. whatever you do to the equation, do it to the enthalpy for that equation. everything should add or cancel until you have the equation needed and you can add the enthalpies to get the enthalpy for that equation
Which occurs faster at equilibrium the formation of products from reactants or reactants from the product?
At equilibrium, the formation of products from reactants will be faster.
In an exothermic reaction is the energy of the products higher or lower than that of the reactants?
In an exothermic reaction the energy of the products is less than that of the reactants.
What are the reactants and products fermentation?
what are the reactants and products of fermentation and acetyl Co A formation
What is H in the equation G H TS?
The change in entropy between products and reactants in a reaction
Thermochemical equations are chemical equations that include the of the reaction.?
Termochemical reactions include the enthalpy of reactants and products.
Would this reaction happen NaCl plus CaF2 - NaF plus CaCl2?
The reaction is2NaCl + CaF2 --> 2NaF + CaCl2and the enthalpies of formation (kJ/Mol) of the solids at STP are2NaCl = (-411)*2CaF2 = -1220Total = -20422NaF = (-469)*2CaCl2 = -796Total = -1734The calculations show that the reactants are more stable than the products by some 307kJ/mol, so that the reaction would not proceed. (For more advanced readers, the value for the Gibbs free energy of formation will not be very much different from this, as the entropy terms will be relatively small in comparison with the enthalpy terms.) A major factor in this is the relatively high lattice enthalpy of CaF2.
What is S in the equation delta G equals delta H minus TdeltaS?
The change in enthalpy between products and reactants in a reaction
What is delta h in the equation delta g delta h - t delta?
The change in enthalpy between products and reactants in a reaction
What phase changes are exothermic and what phase changes are endothermic?
exothermic: when the reactants can convert potential energy (stored energy) into kinetic energy. flow of energy into surroundings, surroundings get warmer. the reactants have more energy that the products. energy is lost. the change in enthalpy is negative. the energy sign is on the right side of the arrow (in the equation). exothermic reactions are bond forming endothermic: reactants convert kinetic energy into potential energy during the formation of the products. causes a decrease in temp of the surroundings because it is drawing the heat from it. products have more energy than the reactants. energy is gained. change in enthalpy is positive. the energy sign is on the left side of the arrow (in the equation). endothermic reactions are bond breaking note - enthalpy is another term for potential energy or heat content, the words can be used interchangeably
What is delta S in the equation delta G delta H - T delta S?
The change in enthalpy between products and reactants in a reaction
