How much heat is produced by the complete combustion of 287 g of CH4?
CH4(g)+2O2(g)→CO2(g)+2H2O(g)ΔH∘rxn=−802.3kJ
CH4 + 2O2 ==> CO2 + 2H2O
dHrxn = (n*dHo products) - (n*dHo reactants).
Look up the dHo formation in your text, notes, net, and calculate.
To calculate the amount of heat produced by the complete combustion of 287 g of CH4, we first need to determine the number of moles of CH4, and then use the stoichiometry of the reaction to find the heat released.
1. Calculate the number of moles of CH4:
To find the number of moles, divide the given mass of CH4 by its molar mass. The molar mass of CH4 (carbon tetrahydride or methane) is 16.04 g/mol for carbon plus 4(1.01 g/mol) for hydrogen, which gives a total molar mass of 16.04 + 4(1.01) = 16.04 + 4.04 = 20.08 g/mol.
Number of moles = Mass / Molar mass
Number of moles = 287 g / 20.08 g/mol
2. Use the stoichiometry of the reaction to find the heat released:
From the balanced chemical equation, we can see that 1 mole of CH4 produces -802.3 kJ of heat energy. Therefore, the heat produced can be calculated using the following equation:
Heat produced = Number of moles of CH4 × ΔH°rxn
Substituting the values we calculated:
Heat produced = (287 g / 20.08 g/mol) × (-802.3 kJ/mol)
Now, we can calculate the heat produced by the complete combustion of 287 g of CH4.
To find out how much heat is produced by the complete combustion of 287 g of CH4 (methane), we can use the concept of stoichiometry and the given enthalpy change value (ΔH∘rxn) for the combustion reaction.
First, let's calculate the moles of CH4 in 287 g using its molar mass:
Molar mass of CH4 = 12.01 g/mol (C) + 4.01 g/mol (H) = 16.04 g/mol
Moles of CH4 = Mass / Molar mass = 287 g / 16.04 g/mol = 17.90 mol
From the balanced equation, we can see that the stoichiometric coefficient of CH4 is 1. That means 1 mole of CH4 produces ΔH∘rxn amount of heat energy.
Now, we can calculate the amount of heat produced for 17.90 moles of CH4:
Heat energy produced = Moles of CH4 × ΔH∘rxn
Heat energy produced = 17.90 mol × -802.3 kJ/mol
Multiplying these values gives:
Heat energy produced = -14,366.77 kJ
Therefore, the complete combustion of 287 g of CH4 produces -14,366.77 kJ (or you can round it to -14,367 kJ) of heat energy.
Note: The negative sign indicates that the reaction is exothermic, meaning heat is released during the reaction.