Carbonates and The Atmosphere Flashcards
Reaction of Calcium Oxide and hydrochloric acid
CaO + 2HCl -> CaCl2 + H2O
Thermal decomposition of calcium carbonate
CaCO3 -> CaO + CO2
Reaction of Calcium Hydroxide and Hydrochloric acid
Ca(OH)2 + 2HCl -> CaCl2 + CO2 + 2H2O
Thermal decomposition of calcium hydrogencarbonate solution
Ca(HCO3)2 -> CaCo3 + H2O + CO2
Complete combustion of pentane (C5H12)
C5H12 -> 5CO2 + 6H2O
Carbon dioxide reacting with lime water
Co2 + Ca(OH)2 -> CaCo3 + H2O
Reaction of methane in a limited supply if oxygen
2CH4 + 3O2 -> 2 Co2 + 4H2O
Dry air consists of:
78% Nitrogen
21% Oxygen
1% Other gases (0.039% Co2 and 0.93% argon)
What is meant by thermally decomposing?
Breaks down on heating
Chemical name of limewater
Calcium Hydroxide
How is carbon monoxide sometimes produced in the home and why is it dangerous?
- Colourless, tasteless and has no smell
- Binds with the haemoglobin rather than oxygen
- Caused by poor ventilation, burning coal and gas or boilers
Explain why boiling removes hardness in the water caused by calcium hydrogencarbonate and state what would be observed
Ca(HCO3)2 -> CaCo3 + H2O + Co2
- Ca2+ becomes part of the solid CaCo3
- Ca2+ is removed from the solution
- Observe white precipitate (limescale)
Uses of calcium carbonate:
- Neutralise soils
- Neutralise gases from power station emissions
- Neutralise excess stomach acid
How has carbon dioxide in atmosphere changed over the past 200 years?
- Been an increase in Co2
- Global temperature has increased
- Correlation, but not necessarily a link
- There are serious consequences (the precautionary principle)
Explain iron seeding
Iron seeding of the oceans fertilise the phytoplankton that can photosynthesise and absorb large amounts of carbon dioxide
Other method of reducing carbon dioxide in atmosphere
Developing means of converting carbon dioxide into hydrocarbons that can be reused as fuel
Ways to reduce carbon dioxide emissions:
- Use less energy e.g use cars less and recycle waste
* Use alternate forms of energy production such as wind farms, wave power and nuclear
How long ago did the earth form
Almost 4.5 billion years ago
What has caused the amount of Co2 in the atmosphere to decrease since 4.5 billion years ago?
- Some CO2 dissolved into the oceans
- Carbon dioxide was incorporated into marine organisms through the food. They eventually formed to carbonate rocks
- Primitive plants started to photosynthesise and converted the CO2 into oxygen
Why is the atmosphere changing slowly?
- Volcanic eruption
- Farming
- Deforestation
- Increased combustion
Uses of Limestone (CaCo3)
- Building material and in manufacturing of iron
- Glass - heated with sand and soda
- Cement - heated with clay in a kiln
- Concrete - mixed with sand, water and crushed rock
- Mortar - mixed with sand and water
What happens in an ion exchange resin?
Salt is added to the resin and as the water passes over, the Ca2+ and Mg2+ ions are replaced with Na+ ions from the salt. The waste is CaCl2 and MgCl2 is washed away
How is limestone obtained?
By quarrying
Reaction of Calcium Carbonate and Hydrochloric Acid
CaCO3(s) + HCl -> CaCl2 + H2O + Co2
what is the chemical name for limewater
calcium hydroxide
why is the combustion of fossil fuels a concern
releases co2 into the air which may contribute to global warming
