Calculate the heat of combustion of this wax in kJ/mol. How much energy is produced per carbon? What is the limiting reagent?
I have the Q=m*C*deltaT equation to be 10460.45 joules using 100.1 grams C25H52, 25 degrees C, and 4.18 J/gC. I don't know how to find how much energy is produced per carbon and what the limiting reagent is?
To calculate the heat of combustion of the wax in kJ/mol, you first need to determine the number of moles of the wax (C25H52) you have.
1. Calculate the molar mass of C25H52:
- Carbon (C) has a molar mass of 12.01 g/mol.
- Hydrogen (H) has a molar mass of 1.01 g/mol.
- The molar mass of C25H52 can be calculated as follows:
(25 × 12.01 g/mol) + (52 × 1.01 g/mol) = total molar mass of C25H52 g/mol
2. Calculate the number of moles:
- Divide the mass of the wax (100.1 g) by its molar mass (calculated above). This will give you the number of moles of C25H52.
Now that you have the number of moles, you can calculate the heat of combustion in kJ/mol. The equation you mentioned, Q = m * C * deltaT, gives you the heat (Q) in joules, not kilojoules. To convert to kilojoules, divide the value by 1000.
As for determining how much energy is produced per carbon and identifying the limiting reagent, you need to consider the stoichiometry of the combustion reaction. The balanced equation for the complete combustion of C25H52 would show the reactants and products involved in the reaction. From the equation, you can determine the number of moles of each reactant required for complete combustion.
For example, if the balanced equation shows that for every 1 mole of C25H52, x moles of carbon dioxide (CO2) are produced, then the energy produced per carbon atom can be calculated. Since there are 25 carbon atoms in C25H52, you can divide the energy produced per mole by 25 to get the energy produced per carbon.
To identify the limiting reagent, you need to compare the moles of the reactants present to the stoichiometric ratio of the balanced equation. The reactant that is present in the lowest amount, relative to the stoichiometric ratio, is the limiting reagent.