During the combustion of 5.00g of octane C8H18, 239.5 kcal is released. Write a balanced equation for the combustion reaction. Are reactants or products favored? What is the sign of change of heat for this reaction? how much energy is released by the combustion of 1.53mol of C8H18? how many moles of octane must be burned to release 483.0kcal/ how many grans of octane must be burned to release 483.0kcal? How many kilocalories are released by the combustion of 18.1g of C8H18?
The question is asking to write a balanced equation with the information given.
The balanced equation for the combustion of octane (C8H18) can be written as follows:
2C8H18 + 25O2 -> 16CO2 + 18H2O
In this reaction, the reactants are octane (C8H18) and oxygen (O2), while the products are carbon dioxide (CO2) and water (H2O).
Reactants are favored in this combustion reaction, as they are consumed to form the products.
The sign of the change of heat for this reaction is negative because heat is being released, indicating an exothermic reaction.
To find out how much energy is released by the combustion of 1.53 mol of C8H18, you can use the given energy value of 239.5 kcal released from 5.00 g of octane:
- Calculate the molar mass of octane (C8H18) = 114.22 g/mol.
- Determine the number of moles of octane in 5.00 g: 5.00 g / 114.22 g/mol = 0.0438 mol.
- Calculate the amount of energy released by 1.53 mol using a proportion:
(239.5 kcal / 0.0438 mol) * 1.53 mol = 84.03 kcal.
To determine how many moles of octane must be burned to release 483.0 kcal of energy, you can use the same proportion as above:
- (239.5 kcal / 0.0438 mol) * x mol = 483.0 kcal.
- Solve for x gives: x = (483.0 kcal * 0.0438 mol) / 239.5 kcal ~ 0.088 mol.
To find out how many grams of octane must be burned to release 483.0 kcal:
- Calculate the molar mass of octane (C8H18) = 114.22 g/mol.
- Determine the amount in grams using the obtained number of moles: 0.088 mol * 114.22 g/mol ~ 10.0 g.
To determine the number of kilocalories released by the combustion of 18.1 g of C8H18:
- Calculate the amount of moles of octane in 18.1 g: 18.1 g / 114.22 g/mol = 0.1588 mol.
- Use a proportion to find the energy released: (239.5 kcal / 0.0438 mol) * 0.1588 mol ~ 868.5 kcal.
To write a balanced equation for the combustion reaction of octane (C8H18), we need to combine it with oxygen (O2) to form carbon dioxide (CO2) and water (H2O).
The balanced equation for this combustion reaction is:
C8H18 + 12.5O2 -> 8CO2 + 9H2O
To determine if reactants or products are favored, we can examine the balanced equation. In this case, since octane and oxygen are reacting to form carbon dioxide and water, the reactants are favored.
The sign of change of heat for this reaction is negative, as indicated by the released heat given in the question (239.5 kcal). When heat is released, it is represented as a negative value.
To find how much energy is released by the combustion of 1.53 mol of C8H18, we need to use the given heat released (239.5 kcal) and the molar mass of C8H18 (114.22 g/mol) to calculate the energy released per mole and then multiply it by 1.53 mol. The calculation would be:
Energy released = 239.5 kcal/1 mol C8H18 * 1.53 mol C8H18 = 366.33 kcal
To determine how many moles of octane must be burned to release 483.0 kcal, we can rearrange the equation for energy released:
moles octane = (kcal of heat released / energy released per mole of octane)
moles octane = 483.0 kcal / (239.5 kcal/1 mol C8H18) ≈ 2.02 mol
To find how many grams of octane must be burned to release 483.0 kcal, we can use the molar mass of octane (114.22 g/mol) to convert moles to grams:
grams octane = moles octane * molar mass of octane
grams octane = 2.02 mol * 114.22 g/mol ≈ 230.61 g
To find how many kilocalories are released by the combustion of 18.1 g of C8H18, we need to use the given mass of C8H18 (18.1 g) and the molar mass of C8H18 (114.22 g/mol) to calculate the number of moles, and then use the balanced equation and the given heat released (239.5 kcal) to calculate the energy released. The calculation would be:
moles C8H18 = 18.1 g / 114.22 g/mol ≈ 0.16 mol
Energy released = moles C8H18 * (kcal of heat released / 1 mol C8H18)
Energy released = 0.16 mol * (239.5 kcal/1 mol C8H18) ≈ 38.32 kcal
You have a chapter here. It would help if you told us exactly what you don't understand. I'll get you started.
2C8H18 + 25O2 ==> 16CO2 + 18H2O + heat
or you may write it as
2C8H18 + 25O2 ==> 16CO2 + 18H2O dH = -239.5 kcal
Note that this is the reaction for the 5.00 g octane and NOT for a mol. It isn't clear from the question which you want.