0
The enthalpy change for a chemical reaction exactly as it is written is what?
Wiki User
∙ 15y ago
The amount of energy that is lost or gained by the products during the reaction.
Wiki User
∙ 15y ago
Wiki User
∙ 10y agoHeat of reaction
Add your answer:
Earn +20 pts
What does the state symbol (aq) mean when written after a chemical compound in a chemical reaction?
The state symbol aq means it dissolves in water when it is written after a chemical compound in a chemical reaction.
Would a reaction with oxygen be a chemical or physical property?
By the very fact that your have written 'reaction' , it is a chemical property.
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
What is a method to indicate reactants and products of a chemical reaction using chemical formulas?
In a correctly written chemical equation, reactants are the substances to the left of the arrow, and products are the substances to the right of the arrow. The reactants are what you have before the reaction starts, and the products are what you have when the reaction is over.
A chemical formula written over the arrow in a chemical equation signifies?
A chemical formula written over the arrow in a chemical equation is that of the catalyst used in the reaction.
Can Chemical equations display information concerning the energies involved in a chemical reaction?
The enthalpy change is usually written at the end of the equation. For instance, when hydrogen burns (apologies for the lack of subscripts) 2H2 + O2 = 2H2O Δ H = - 286 kJ per mol
What does the state symbol mean when written after a chemical compound in a chemical reaction?
The state symbol aq means it dissolves in water when it is written after a chemical compound in a chemical reaction.
What does the state symbol (aq) mean when written after a chemical compound in a chemical reaction?
The state symbol aq means it dissolves in water when it is written after a chemical compound in a chemical reaction.
Would a reaction with oxygen be a chemical or physical property?
By the very fact that your have written 'reaction' , it is a chemical property.
What has the author Peter Gray written?
Peter Gray has written: 'Chemical oscillations and instabilities' -- subject(s): Chemical reaction, Rate of, Nonlinear theories, Rate of Chemical reaction
What tells the story of a chemical reaction?
The written statement that shows a chemical reaction is called an "equation". The representation of each reactant is called its chemical formula.
Chemical equation has how many parts?
Most chemical equations have a few standard elements (no pun intended). There are the reactants on the left side, the arrow showing the direction of the reaction, and the products on the right side. Sometimes, properties of the reaction such as the enthalpy is shown after the equation. Often times, especially in organic chemistry, there will be other compounds or parameters written above and/or below the reaction arrow to indicate what chemicals were needed to make the reaction occur.
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
What has the author James Arthur Campbell written?
James Arthur Campbell has written: 'Why do chemical reactions occur?' -- subject(s): Chemical reaction, Conditions and laws of, Conditions and laws of Chemical reaction
What is the written chemical reaction that occurs when you mix potassium and water?
The chemical reaction is:2 K + 2 H2O = 2 KOH + H2
What is the difference between a thermodynamically favorable and a thermodynamically unfavorable reaction?
Enthalpy change is not the only consideration for whether a reaction is favorable. However, if the enthalpy change is large, it is usually the dominant factor in determining favorability. Therefore, reactions that have a large, negative tend to be favorable, because the reaction usually releases energy when it occurs. Reactions that have a large, positive tend to be unfavorable as written, because the reaction usually requires energy to occur.
What has the author NB Chapman written?
N.B Chapman has written: 'Advances in linear free energy relationship' -- subject(s): Chemical reaction, Conditions and laws of, Conditions and laws of Chemical reaction
