Thermochemical equation A balanced

There are three different ways to represent the enthalpy change of an exothermic reaction. The simplest way is to use a thermochemical equation a balanced chemical equation that indicates the amount of heat that is absorbed or released by the reaction it represents. For example, consider the exothermic reaction of one mole of hydrogen gas with half a mole of oxygen gas to produce liquid water. For each mole of hydrogen gas that reacts, 285.8 kj of heat is produced. Notice that the heat term is included with the products because heat is produced. 

Thermochemical equation A balanced chemical equation together with a designation of the corresponding value of Sometimes used with changes in other thermodynamic quantities. 

A chemical equation that shows the enthalpy relation between products and reactants is called a thermochemical equation. This type of equation contains, at the right of the balanced chemical equation, the appropriate value and sign for AH. 

Al(s) + Fe203(s) —> Al203(s) + 2Fe(l). thermochemical equation An expression consisting of both the balanced chemical equation and the reaction enthalpy for the chemical reaction exactly as written, thermochemistry The study of the heat released or absorbed by chemical reactions a branch of thermodynamics. 

Just as an ordinary chemical equation is a shortened version of the complete thermochemical equation which expresses both energy and mass balance, each nuclear equation has a term (written or implied) expressing energy balance. The symbol Q is usually used to designate the net energy released when all reactant and product particles of matter are at zero velocity. Q is the energy equivalent of the mass decrease (discussed above) accompanying the reaction. Q is usually expressed in MeV. 

A thermochemical equation must be balanced, include all states of each reactant and product, and list the enthalpy for the reaction. An example of such a reaction is shown below ... 

Sample The complete combustion of butane gas, C4H10, in oxygen gas, Oz, produces C02 and H20. It is a highly exothermic process releasing 2845 kj of heat per mole of butane. Write the balanced thermochemical equation, using all whole-number coefficients. Also, determine the enthalpy change in burning 50.0 g of butane gas. 

A thermochemical equation shows a balanced chemical equation and the enthalpy of the... 

Consider bond breaking and bond making to explain why the combustion of acetylene is exothermic. Then write a thermochemical equation for the reaction, using the following balanced equation ... 

How can a balanced thermochemical equation tell you whether a chemical reaction is exothermic or endothermic ... 

A thermochemical equation is a balanced chemical equation that includes the physical states of all reactants and products and the energy change, usually expressed as the change in enthalpy, Mi. 

How is a thermochemical equation different from a balanced chemical equation (16.3)... 

A balanced chemical equation, together with its value of A//, is called a thermochemical equation. For example,... 

The coefficients in a balanced thermochemical equation refer to the numbers of moles of reactants and products involved. In the thermodynamic interpretation of equations we never interpret the coefficients as numbers of molecules. Thus, it is acceptable to write coefficients as fractions rather than as integers, when necessary. 

Here a, b, c,. .. refer to balanced thermochemical equations that can be summed to give the equation for the desired reaction. 

A thermochemical equation is a balanced equation that includes the heat of reaction (A//rxn). Keep in mind that the A//,xn value shown refers to the amounts (moles) of substances and their states of matter in that specific equation. The enthalpy change of any process has two aspects ... 

A thermochemical equation shows the balanced equation and its AHrxn- The sign of AH for a forward reaction is opposite that for the reverse reaction. The magnitude of AH depends on the amount and physical state of the substance reacting and the AH per mole of substance. We use the thermochemically equivalent amounts of substance and heat from the balanced equation as conversion factors to find the quantity of heat when a given amount of substance reacts. 

Consider the following balanced thermochemical equation for a reaction sometimes used for H2S production ... 

When 1 mol of NO(g) forms from its elements, 90.29 kJ of heat is absorbed, (a) Write a balanced thermochemical equation for this reaction, (b) How much heat is involved when 1.50 g of NO decomposes to its elements ... 

The decomposition of slaked lime, Ca(OH)2(s), into lime, CaO(s), and H20(g) at constant pressure requires the addition of 109 kJ of heat per mole of Ca(OH)2. (a) Write a balanced thermochemical equation for the reaction, (b) Draw an enthalpy diagram for the reaction. 

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