Combustion of Alkenes

• What is complete combustion of alkanes?

  Combustion with excess oxygen producing CO₂ and H₂O
• What is the general equation for complete combustion of alkanes?

  $C_xH_y +$$(x + \frac{y}{4})O_2 \rightarrow xCO_2 +$$\frac{y}{2}H_2O$
• What is incomplete combustion?

  Combustion with limited oxygen producing CO and soot
• Why is carbon monoxide dangerous?

  It binds to hemoglobin, reducing oxygen transport
• What pollutants are produced by internal combustion engines?

  Nitrogen oxides, carbon monoxide, unburned hydrocarbons, particulates
• How are nitrogen oxides (NOx) formed in engines?

  Nitrogen and oxygen react at high temperatures
• What are the harmful effects of nitrogen oxides (NOx)?

  They contribute to acid rain and photochemical smog
• What is the function of a catalytic converter?

  To reduce harmful emissions from vehicle exhaust
• Write the equation for the oxidation of carbon monoxide in a catalytic converter.

  $2CO +$$O_2 \rightarrow 2CO_2$
• Write the equation for the reduction of nitrogen oxides in a catalytic converter.

  $2NO +$$2CO \rightarrow N_2 +$$2CO_2$
• Write the equation for the oxidation of unburned hydrocarbons in a catalytic converter.

  $C_xH_y +$$O_2 \rightarrow CO_2 +$$H_2O$
• What pollutants are produced by the combustion of sulfur-containing hydrocarbons?

  Sulfur dioxide (SO₂), contributing to acid rain
• How is sulfur dioxide (SO₂) removed from flue gases?

  Using calcium oxide or calcium carbonate in desulfurization
• Write the equation for SO₂ removal using calcium oxide (CaO).

  $SO_2 +$$CaO \rightarrow CaSO_3$
• Write the equation for SO₂ removal using calcium carbonate (CaCO₃).

  $SO_2 +$$CaCO_3 \rightarrow CaSO_3 +$$CO_2$
• What is formed after the reaction between SO₂ and calcium oxide or carbonate?

  Calcium sulfite (CaSO₃), which can oxidize to gypsum
• What is the structure of a catalytic converter?

  A honeycomb structure coated with precious metals
• What are the main harmful effects of carbon (soot)?

  Causes respiratory problems and reduces air quality
• What are unburned hydrocarbons, and why are they harmful?

  They escape combustion and contribute to smog
• Why are catalytic converters important in reducing air pollution?

  They convert harmful pollutants into less harmful products
• Why is sulfur dioxide (SO₂) a major environmental concern?

  It causes acid rain, damaging ecosystems and infrastructure
• What are the products of the complete combustion of methane (CH₄)?

  Carbon dioxide (CO₂) and water (H₂O)
• What happens when calcium sulfite (CaSO₃) is further oxidized?

  It forms gypsum (CaSO₄·2H₂O) for building materials
• How do catalytic converters help reduce smog formation?

  They remove NOx and unburned hydrocarbons