When methane is combusted with excess oxygen 891 kJ of energy is produced start with 100g of methane. how much energy is produced?
is this reaction endothermic or exothermic?
Also provide enthalpy change for this reaction:
CH4 + 2O2 (arrow)= CO2 + H2O + 891 kJ
terrible website..?
To calculate the amount of energy produced when 100g of methane is combusted, we need to use the given information that 891 kJ of energy is produced per mole of methane.
First, we need to determine the number of moles of methane in 100g. The molar mass of methane (CH4) is 16.04 g/mol (1 carbon atom with a molar mass of 12.01 g/mol and 4 hydrogen atoms with a total molar mass of 1.01 g/mol).
Number of moles of methane = Mass of methane / Molar mass of methane
Number of moles of methane = 100g / 16.04 g/mol ≈ 6.23 mol
Since the stoichiometric coefficient of methane in the balanced chemical equation is 1, we can conclude that for every mole of methane combusted, 891 kJ of energy is produced.
Energy produced = Number of moles of methane × Energy per mole of methane
Energy produced = 6.23 mol × 891 kJ/mol ≈ 5547 kJ
Therefore, when 100g of methane is combusted, around 5547 kJ of energy is produced.
Now, to determine if the reaction is endothermic or exothermic, we look at the sign of the enthalpy change. In this case, the reaction is exothermic because the enthalpy change is negative. The 891 kJ of energy released during the reaction indicates that more energy is given off than is taken in, which is a characteristic of an exothermic reaction.
Lastly, the enthalpy change for this reaction is -891 kJ/mol because it is the amount of energy released per mole of methane combusted.