Question

Many power plants produce energy by burning carbon-based fuels, which also produces carbon dioxide. Carbon dioxide is a greenhouse gas, so over-production can have negative effects on the environment. Use enthalpy of formation data to calculate the number of moles of CO₂(g) produced per megajoule of heat released from the combustion of each fuel under standard conditions (1 atm and 25°C).

Each must be in mol * MJ⁻¹
(a) coal, C(s, graphite)
(b) natural gas, CH₄(g);
(c) propane, C₃H₈(g);
(d) octane, C₈H₁₈(l) (?Hf = 250.1 kJ mol⁻¹).

Answer 1

To calculate the number of moles of CO₂(g) produced per megajoule of heat released from the combustion of each fuel, use the enthalpy of formation data. Calculate the moles of CO₂ produced by each fuel (coal, natural gas, propane, and octane) using the molar masses of the respective fuels and CO₂.

Step-by-step explanation:

To calculate the number of moles of CO₂(g) produced per megajoule of heat released from the combustion of each fuel, we need the enthalpy of formation data for each fuel. Using the enthalpy of formation of CO₂(g) and the heat released from combustion of each fuel, we can calculate the moles of CO₂ produced per megajoule of heat released.

(a) Coal, C(s, graphite): The enthalpy of formation of CO₂ is -393.5 kJ/mol. The heat released from the combustion of coal is 2.5 x 10⁶ J/kg. To convert this to MJ and calculate the moles of CO₂ produced, we need the molar mass of carbon and CO₂.

(b) Natural gas, CH₄(g): The enthalpy of formation of CO₂ is -393.5 kJ/mol. The heat released from the combustion of natural gas is also 2.5 x 10⁶ J/kg. To calculate the moles of CO₂ produced, we need the molar masses of methane and CO₂.

(c) Propane, C₃H₈(g): The enthalpy of formation of CO₂ is -393.5 kJ/mol. The heat released from the combustion of propane is 2.5 x 10⁶ J/kg. To calculate the moles of CO₂ produced, we need the molar mass of propane and CO₂.

(d) Octane, C₈H₁₈(l): The enthalpy of formation of CO₂ is -393.5 kJ/mol. The heat released from the combustion of octane is 2.5 x 10⁶ J/kg. To calculate the moles of CO₂ produced, we need the molar mass of octane and CO₂.