Calculate Heat of Combustion of C2H2

In summary, the molar heat of combustion of C2H2 can be calculated by balancing the combustion equation, summing the heat of the products and the heat of the reactants, and dividing by the number of moles of C2H2 present. The resulting value is an exothermic reaction with a heat of combustion of -1046.1 kJ/mol.
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Homework Statement



Given the following enthalpies calculate the molar heat of combustion of C2H2.

Heat of formation of liquid water: -285.8 kJ/mol
Heat of formation of C2H2 (gas): -26.7 kJ/mol
Heat of formation of CO2 (gas): -393.5 kJ/mol

Homework Equations



Heat of combustion is heat of products minus heat of reactants.

The Attempt at a Solution



I balance the equation and I get:

2C2H2 + 5O2 => 4CO2 + 2H2O

The sum of the heat of the products minus the sum of the heat of the reactants, with the heat of oxygen being 0, is 2092.2 kJ.

Since there are two moles of C2H2 being combusted we must divide by 2 and we get 1046.1 kJ/mol.

Since this is combustion this is an exothermic reaction and so the heat of combustion is -1046.1 kJ/mole.

Is this correct?
 
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Logic is sound.
 
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Related to Calculate Heat of Combustion of C2H2

1. What is the definition of heat of combustion?

The heat of combustion, also known as the enthalpy of combustion, is the amount of heat released when a substance undergoes complete combustion with oxygen.

2. How is the heat of combustion calculated?

The heat of combustion can be calculated by measuring the temperature change of the surroundings during the combustion reaction and using the equation q = m x c x ∆T, where q is the heat released, m is the mass of the substance, c is the specific heat capacity, and ∆T is the change in temperature.

3. What is the importance of calculating the heat of combustion of C2H2?

C2H2, also known as acetylene, is a common industrial gas used in welding and cutting. Knowing the heat of combustion of C2H2 helps in determining the efficiency and potential energy output of using this gas as a fuel source.

4. What factors can affect the heat of combustion of C2H2?

The heat of combustion of C2H2 can be affected by factors such as the purity of the gas, the amount of oxygen available for the reaction, and the temperature and pressure of the surroundings.

5. Can the heat of combustion of C2H2 be different in different environments?

Yes, the heat of combustion of C2H2 can vary in different environments due to factors such as the presence of impurities or variations in the temperature and pressure of the surroundings. It is important to specify the conditions under which the heat of combustion is measured for accurate results.

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