Hydrocarbons – Learning Outcomes Recall that fossil fuels are sources of hydrocarbons. Recall that hydrocarbons produce CO2 and H2O when burned. Give two examples of fossil fuels. Describe the composition of natural gas. HL: Describe the role of fuel combustion and SO2 in the production of acid rain. HL: Describe the effects of acid rain. Describe the effect of acid rain on limestone and plants.

Recall about Hydrocarbons Hydrocarbons are made entirely of hydrogen and carbon. One source of hydrocarbons is fossil fuels (coal, oil, gas, peat). These are fuels formed from the remains of plants and animals that died millions of years ago (hence “fossil” fuels). Burning these produces carbon dioxide (CO2) and water (H2O). (How could you test for these?) Natural gas is mostly methane (CH4).

HL: Describe Acid Rain Production One product of coal and oil burning is sulfur dioxide (SO2). SO2 dissolves in water to form sulfuric acid (H2SO4). This is the main cause of acid rain (rain with pH below 5.5).

Describe Effects of Acid Rain Rising acidity levels in lakes and oceans is killing fish and preventing shellfish from forming shells. Acid rain removes minerals in soil, affecting plant growth. Acid rain can wear away rocks (in particular limestone), damaging buildings and artwork. by Lovecz – public domain by Slick – CC0

Describe Effects of Acid Rain How to reduce acid rain: Filter emissions from power stations to remove sulfur dioxide. Treat fuels to remove sulfur compounds. Install catalytic converters in cars, which remove nitric oxides, which also contribute to acid rain. Convert power production to non-fossil fuel-based sources.