Pentane is a small liquid hydrocarbon, between propane and gasoline in size C5H12. The density of pentane is 0.626g/ml and its enthalpy of combustion is ΔHcomb =-3535kj/mol. Estimate the fuel valve and the fuel density of pentane.
To estimate the fuel value and the fuel density of pentane, we will use the enthalpy of combustion (ΔHcomb) and the density of pentane.
1. Fuel Value:
The fuel value, also known as the heat of combustion, represents the amount of energy released when a substance is completely burned. It is given by the enthalpy of combustion per mole of substance.
In this case, the enthalpy of combustion of pentane is given as ΔHcomb = -3535 kJ/mol.
To find the fuel value per gram of pentane, we need to calculate the molar mass of pentane (C5H12), which is given by:
5 * atomic mass of carbon (C) + 12 * atomic mass of hydrogen (H)
Using the atomic masses from the periodic table:
Atomic mass of carbon (C) = 12.01 g/mol
Atomic mass of hydrogen (H) = 1.01 g/mol
Molar mass of pentane (C5H12) = 5 * 12.01 g/mol + 12 * 1.01 g/mol = 72.13 g/mol
Now, we can calculate the fuel value per gram of pentane:
Fuel value per gram = ΔHcomb / molar mass of pentane
Fuel value per gram = -3535 kJ/mol / 72.13 g/mol
Solving this equation will give us the fuel value per gram of pentane.
2. Fuel Density:
The fuel density of pentane is given as 0.626 g/ml.
To convert this value to g/cm³ (grams per cubic centimeter) or kg/m³ (kilograms per cubic meter), we just need to recall that 1 ml is equivalent to 1 cm³. Therefore, the fuel density of pentane can be expressed as:
Fuel density = 0.626 g/ml = 0.626 g/cm³ (or you can convert it to kg/m³ if needed)
By following this process, you can estimate the fuel value and the fuel density of pentane using the given information.