Question

Lightweight camping stoves typically use white gas, a mixture of C5 and C6 hydrocarbons.

A) Calculate the fuel value of C5H12, given that the change in H comb= -3535kJ/mol
B) How much heat is released during the combustion of 1.42 kg of C5H12
C) How many grams of C5H12 must be burned to heat 1.09 kg of water from 23.7 C to 96.3 C? Assume that all the heat released during the combustion is used to heat the water

Answer 1

To determine the fuel value and heat release of white gas combustion, utilize the enthalpy change and specific heat capacity formulas. Calculate moles from mass for total heat release, and apply the specific heat capacity for heat required to warm water.

Step-by-step explanation:

The energy content of a fuel is the amount of heat produced by the combustion of a unit quantity of the fuel. The combustion of white gas, which is a mixture of C5 and C6 hydrocarbons, can be used in lightweight camping stoves. To calculate the fuel value and heat released during combustion, we use the given enthalpy change and the mass of the fuel burned.

Answer 2

To calculate the fuel value of C5H12, we can use the change in enthalpy of combustion per mole of C5H12. The heat released during the combustion of 1.42 kg of C5H12 can be calculated using the fuel value and mass of C5H12. To find the mass of C5H12 required to heat 1.09 kg of water, we can use the heat required and the fuel value.

Step-by-step explanation:

To find the fuel value of C5H12, we need to use the given change in enthalpy of combustion (ΔH comb = -3535 kJ/mol). The fuel value is equal to the change in enthalpy of combustion per mole of C5H12. Since the stoichiometry of the balanced combustion equation is not given, we can assume that the equation is:

C5H12 + 8O2 -> 5CO2 + 6H2O

Using this equation, we can calculate the fuel value as follows:

ΔH comb (per mole of C5H12) = -3535 kJ/mol / 1 mol C5H12

ΔH comb (per gram of C5H12) = -3535 kJ/mol / molar mass of C5H12

To calculate the heat released during the combustion of 1.42 kg of C5H12, we can use the fuel value calculated above. The heat released (in kJ) is equal to the fuel value multiplied by the mass of C5H12:

Heat released = fuel value * mass of C5H12

To find the number of grams of C5H12 that must be burned to heat 1.09 kg of water from 23.7°C to 96.3°C, we need to calculate the heat required to raise the temperature of the water. The heat required can be calculated using the formula:

Heat required = mass of water * specific heat capacity of water * temperature difference

Once we have the heat required, we can use the fuel value calculated earlier to find the mass of C5H12 required:

Mass of C5H12 = Heat required / fuel value