State the differences between Gaseous fuels and solid fuels. A gaseous fuel has the following composition: CH 4 = 38%, H 2 = 26%, N 2 = 6%, CO = 26% and CO 2 = 4%. Find the stoichiometric air/fuel ratio by volume.

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Asked on July 16, 2026Chemistry

This chemistry question involves key chemical concepts and calculations. The detailed solution below walks through each step, from identifying the reaction type to computing the final answer.

Accepted Answer · 2026-07-16T17:57:37.972Z

Here are the solutions to your questions. 2. a) State the differences between Gaseous fuels and solid fuels. Gaseous Fuels: Easier to handle and transport (e.g., via pipelines). Burn cleanly with minimal ash and particulate matter. Combustion rate is easier to control. Require specialized storage (e.g., pressurized tanks). Solid Fuels: Easier to store in bulk (e.g., piles). Produce significant ash and particulate matter upon combustion. Combustion rate is more challenging to control. Transportation often requires heavy machinery. 2. b) A gaseous fuel has the following composition: CH_4 = 38\%, H_2 = 26\%, N_2 = 6\%, CO = 26\% and CO_2 = 4\%. Find the stoichiometric air/fuel ratio by volume. Step 1: Write the balanced combustion equations for each combustible component and determine the oxygen required. Assume 100 volumes of fuel. For CH_4 (38 volumes): CH_4 + 2O_2 CO_2 + 2H_2O Oxygen required: 38 × 2 = 76 volumes of O_2. For H_2 (26 volumes): H_2 + (1)/(2)O_2 H_2O Oxygen required: 26 × (1)/(2) = 13 volumes of O_2. For CO (26 volumes): CO + (1)/(2)O_2 CO_2 Oxygen required: 26 × (1)/(2) = 13 volumes of O_2. N_2 (6 volumes) and CO_2 (4 volumes) are inert and do not require oxygen for combustion. Step 2: Calculate the total oxygen required. Total oxygen required per 100 volumes of fuel = 76 + 13 + 13 = 102 volumes of O_2. Step 3: Calculate the volume of air required. Air is approximately 21% oxygen by volume. Volume of air required = Total oxygen requiredFraction of oxygen in air V_air = 102 volumes0.21 ≈ 485.71 volumes of air Step 4: Calculate the stoichiometric air/fuel ratio by volume. Air/fuel ratio by volume = Volume of air requiredVolume of fuel Air/Fuel Ratio = 485.71 volumes of air100 volumes of fuel ≈ 4.857 The stoichiometric air/fuel ratio by volume is 4.857. 3. a) State the steady flow energy equation. The Steady Flow Energy Equation (SFEE) for a single inlet and single outlet system is given by: Q - W = m [ (h_2 - h_1) + (V_2^2 - V_1^2)/(2) + g(z_2 - z_1) ] where: Q is the rate of heat transfer to the system. W is the rate of work done by the system. m is the mass flow rate. h is the specific enthalpy (h = u + Pv). V is the velocity. g is the acceleration due to gravity. z is the elevation. Subscripts 1 and 2 denote inlet and outlet conditions, respectively. 3. b) In a steady flow system, a substance flows at a rate of 5.2 kg/sec. It enters at a pressure of 620 kN/m^2, a velocity of 298 m/sec, internal energy 2100 kJ/kg, and specific volume 0.37 m^3/kg. It leaves at a pressure of 130 kN/m^2, a velocity of 145 m/sec, internal energy 1500 kJ/kg, and specific volume 1.2 m^3/kg. During its passage through the system, the substance rejects 120 kJ/sec of heat. Determine the work done per kg of the substance. Given data: Mass flow rate m = 5.2 kg/s Inlet (State 1): P_1 = 620 kPa, V_1 = 298 m/s, u_1 = 2100 kJ/kg, v_1 = 0.37 m^3/kg Exit (State 2): P_2 = 130 kPa, V_2 = 145 m/s, u_2 = 1500 kJ/kg, v_2 = 1.2 m^3/kg Heat rejected Q_out = 120 kJ/s. Therefore, heat added to the system Q = -120 kJ/s. Assume negligible change in potential energy (g(z_2 - z_1) = 0). The SFEE per unit mass is: q - w = (h_2 - h_1) + (V_2^2 - V_1^2)/(2) We need to find w, the work done per kg. So, w = q - (h_2 - h_1) - (V_2^2 - V_1^2)/(2). Step 1: Calculate the specific heat transfer q. q = Qm = -120 kJ/s5.2 kg/s ≈ -23.0769 kJ/kg Step 2: Calculate the specific enthalpy at the inlet (h_1) and outlet (h_2). Specific enthalpy h = u + Pv. h_1 = u_1 + P_1 v_1 = 2100 kJ/kg + (620 kPa × 0.37 m^3/kg) h_1 = 2100 kJ/kg + 229.4 kJ/kg = 2329.4 kJ/kg h_2 = u_2 + P_2 v_2 = 1500 kJ/kg + (130 kPa × 1.2 m^3/kg) h_2 = 1500 kJ/kg + 156 kJ/kg = 1656 kJ/kg Step 3: Calculate the change in specific enthalpy (h_2 - h_1). h_2 - h_1 = 1656 kJ/kg - 2329.4 kJ/kg = -673.4 kJ/kg Step 4: Calculate the change in kinetic energy. (V_2^2 - V_1^2)/(2) = (145 m/s)^2 - (298 m/s)^22 = 21025 m^2/s^2 - 88804 m^2/s^22 = -67779 m^2/s^22 = -33889.5 J/kg = -33.8895 kJ/kg Step 5: Calculate the work done per kg (w). w = q - (h_2 - h_1) - (V_2^2 - V_1^2)/(2) w = -23.0769 kJ/kg - (-673.4 kJ/kg) - (-33.8895 kJ/kg) w = -23.0769 + 673.4 + 33.8895 kJ/kg w = 684.2126 kJ/kg The work done per kg of the substance is 684.21 kJ/kg. Got more? Send 'em!

Accepted Answer · 2026-07-16T17:57:37.972Z

Here are the solutions to your questions. 2. a) State the differences between Gaseous fuels and solid fuels. Gaseous Fuels: Easier to handle and transport (e.g., via pipelines). Burn cleanly with minimal ash and particulate matter. Combustion rate is easier to control. Require specialized storage (e.g., pressurized tanks). Solid Fuels: Easier to store in bulk (e.g., piles). Produce significant ash and particulate matter upon combustion. Combustion rate is more challenging to control. Transportation often requires heavy machinery. 2. b) A gaseous fuel has the following composition: CH_4 = 38\%, H_2 = 26\%, N_2 = 6\%, CO = 26\% and CO_2 = 4\%. Find the stoichiometric air/fuel ratio by volume. Step 1: Write the balanced combustion equations for each combustible component and determine the oxygen required. Assume 100 volumes of fuel. For CH_4 (38 volumes): CH_4 + 2O_2 CO_2 + 2H_2O Oxygen required: 38 × 2 = 76 volumes of O_2. For H_2 (26 volumes): H_2 + (1)/(2)O_2 H_2O Oxygen required: 26 × (1)/(2) = 13 volumes of O_2. For CO (26 volumes): CO + (1)/(2)O_2 CO_2 Oxygen required: 26 × (1)/(2) = 13 volumes of O_2. N_2 (6 volumes) and CO_2 (4 volumes) are inert and do not require oxygen for combustion. Step 2: Calculate the total oxygen required. Total oxygen required per 100 volumes of fuel = 76 + 13 + 13 = 102 volumes of O_2. Step 3: Calculate the volume of air required. Air is approximately 21% oxygen by volume. Volume of air required = Total oxygen requiredFraction of oxygen in air V_air = 102 volumes0.21 ≈ 485.71 volumes of air Step 4: Calculate the stoichiometric air/fuel ratio by volume. Air/fuel ratio by volume = Volume of air requiredVolume of fuel Air/Fuel Ratio = 485.71 volumes of air100 volumes of fuel ≈ 4.857 The stoichiometric air/fuel ratio by volume is 4.857. 3. a) State the steady flow energy equation. The Steady Flow Energy Equation (SFEE) for a single inlet and single outlet system is given by: Q - W = m [ (h_2 - h_1) + (V_2^2 - V_1^2)/(2) + g(z_2 - z_1) ] where: Q is the rate of heat transfer to the system. W is the rate of work done by the system. m is the mass flow rate. h is the specific enthalpy (h = u + Pv). V is the velocity. g is the acceleration due to gravity. z is the elevation. Subscripts 1 and 2 denote inlet and outlet conditions, respectively. 3. b) In a steady flow system, a substance flows at a rate of 5.2 kg/sec. It enters at a pressure of 620 kN/m^2, a velocity of 298 m/sec, internal energy 2100 kJ/kg, and specific volume 0.37 m^3/kg. It leaves at a pressure of 130 kN/m^2, a velocity of 145 m/sec, internal energy 1500 kJ/kg, and specific volume 1.2 m^3/kg. During its passage through the system, the substance rejects 120 kJ/sec of heat. Determine the work done per kg of the substance. Given data: Mass flow rate m = 5.2 kg/s Inlet (State 1): P_1 = 620 kPa, V_1 = 298 m/s, u_1 = 2100 kJ/kg, v_1 = 0.37 m^3/kg Exit (State 2): P_2 = 130 kPa, V_2 = 145 m/s, u_2 = 1500 kJ/kg, v_2 = 1.2 m^3/kg Heat rejected Q_out = 120 kJ/s. Therefore, heat added to the system Q = -120 kJ/s. Assume negligible change in potential energy (g(z_2 - z_1) = 0). The SFEE per unit mass is: q - w = (h_2 - h_1) + (V_2^2 - V_1^2)/(2) We need to find w, the work done per kg. So, w = q - (h_2 - h_1) - (V_2^2 - V_1^2)/(2). Step 1: Calculate the specific heat transfer q. q = Qm = -120 kJ/s5.2 kg/s ≈ -23.0769 kJ/kg Step 2: Calculate the specific enthalpy at the inlet (h_1) and outlet (h_2). Specific enthalpy h = u + Pv. h_1 = u_1 + P_1 v_1 = 2100 kJ/kg + (620 kPa × 0.37 m^3/kg) h_1 = 2100 kJ/kg + 229.4 kJ/kg = 2329.4 kJ/kg h_2 = u_2 + P_2 v_2 = 1500 kJ/kg + (130 kPa × 1.2 m^3/kg) h_2 = 1500 kJ/kg + 156 kJ/kg = 1656 kJ/kg Step 3: Calculate the change in specific enthalpy (h_2 - h_1). h_2 - h_1 = 1656 kJ/kg - 2329.4 kJ/kg = -673.4 kJ/kg Step 4: Calculate the change in kinetic energy. (V_2^2 - V_1^2)/(2) = (145 m/s)^2 - (298 m/s)^22 = 21025 m^2/s^2 - 88804 m^2/s^22 = -67779 m^2/s^22 = -33889.5 J/kg = -33.8895 kJ/kg Step 5: Calculate the work done per kg (w). w = q - (h_2 - h_1) - (V_2^2 - V_1^2)/(2) w = -23.0769 kJ/kg - (-673.4 kJ/kg) - (-33.8895 kJ/kg) w = -23.0769 + 673.4 + 33.8895 kJ/kg w = 684.2126 kJ/kg The work done per kg of the substance is 684.21 kJ/kg. Got more? Send 'em!

State the differences between Gaseous fuels and solid fuels. A gaseous fuel has the following composition: CH 4 = 38%, H 2 = 26%, N 2 = 6%, CO = 26% and CO 2 = 4%. Find the stoichiometric air/fuel ratio by volume.

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State the differences between Gaseous fuels and solid fuels. A gaseous fuel has the following composition: CH 4 = 38%, H 2 = 26%, N 2 = 6%, CO = 26% and CO 2 = 4%. Find the stoichiometric air/fuel ratio by volume.

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