Non-Metals & Their Compounds - Unit 2 Topic 8 Flashcards
What are the physical properties of hydrogen?
Colourless, odourless gas, lighter than air, insoluble in air + burns explosively in air.
What are the 2 equations if hydrogen reacts with:
- Oxygen
- CuO
2H2 + O2 -> 2H2O
H2 + CuO -> Cu + H2O
What general equation do we use to prepare hydrogen?
Metal + acid -> salt + hydrogen
What is a clean fuel?
Fuel which when burned doesn’t produce any toxic or polluting products.
What are the benefits of using hydrogen as a fuel?
Clean fuel + can be used safely in fuel cells.
What are the drawbacks of using hydrogen as a fuel?
Must be manufactured as not naturally abundant, fuel cells expensive, very flammable and leaks hard to detect, storage tanks must be well insulated to prevent liquid H2 turning to gas and escaping.
Give 3 uses for hydrogen?
Clean fuel, rocket engines + meteorological balloons.
What are 3 uses of carbon dioxide?
Fire extinguisher, carbonated drinks + dry ice.
What are the physical properties of carbon dioxide?
Colourless, odourless gas, heavier than air, slightly soluble in water, doesn’t support combustion + acidic.
What is the test for carbon dioxide? (Equation)
What if there is excess CO2?
Bubbled through limewater, turns milky-cloudy.
CO2 + Ca(OH)2 -> CaCO3 + H2O
Turns back to colourless
CO2 + CaCO3 + H2O -> Ca(HCO3)2
What do you notice at the rim of a bottle of sodium hydroxide?
White crust.
Give 3 observations when CaCO3 reacts with HCl
Disappears, fizzing, exothermic.
What is the formula for carbonic acid?
H2CO3
What happens when a piece of burning Mg is put into a jar of CO2?
Continues to burn with bright white light, black soot forms + white ash forms.
What are the physical properties of nitrogen?
Colourless, odourless, same weight as air, insoluble in water + doesn’t burn.
What are 2 uses of nitrogen?
Coolant + food packaging.
What are the physical properties of oxygen?
Gas, colourless, odourless, same weight as air + supports combustion.
What are 3 uses for oxygen?
Medicine, welding + rocket engines.
What is the test for oxygen?
Relights a glowing splint.
How do we collect oxygen when we make a sample?
Over water as it’s only slightly soluble in water.
What is the definition of combustion?
Fuel reacting with oxygen to produce oxides and energy.
What are the physical properties of ammonia?
Colourless gas, characteristic smell, lighter than air, very soluble in water + produces an alkaline solution.
How is ammonia collected?
Ammonia Fountain Experiment. Water injected into flask which dissolves ammonia and pressure increases which draws up water from trough.
What are the advantages of nitrogenous fertilisers?
Greater nitrogen uptake by plant which makes them larger + healthier.
Increases crop yield + profit.
What are the disadvantages of nitrogenous fertilisers?
If fertiliser gets into rivers, eutrophication.
In drinking water causes stomach cancer + gives babies blue baby syndrome.
What can aqueous ammonia be used for?
Testing for the presence of metal ions in solutions.
Aqueous ammonia precipitate colours: Mg2+ Cu2+ Al3+ Fe2+ Fe3+ Zn2+
White Pale blue White Green Red-brown White
Aqueous ammonia excess NaOH solubility: Mg2+ Cu2+ Al3+ Fe2+ Fe3+ Zn2+
No Yes dark blue solution No No No Yes colourless solution
What process is used to make ammonia?
What reactants, temperature, pressure + catalyst?
What percentage of gases react to form ammonia?
Is it reversible?
The haber process
Nitrogen + hydrogen, 450c, 200atm, Iron.
20%.
Yes.
The highest % yield of ammonia is produced in ultra high pressure, why is this not used?
Very expensive and dangerous.
The % yield of ammonia is increased at low temp, why isn’t this used?
Catalyst won’t work below 450c.
What colour is sulfur?
What flame colour is sulfur?
What are the 3 allotropes of sulfur?
Yellow solid
Blue flame
Rhombic sulfur, monoclinic sulfur + plastic sulfur.
What is an allotrope?
Different forms of the same element in the same physical state.
What are the physical properties of sulfur dioxide?
Yellow, pungent gas. Heavier than air, soluble in water + forms acidic solution.
What is sulfur present in?
Fossil fuels
What effect does acid rain have when it falls on a forest?
Difficulty in photosynthesising as leaf damaged + leaches nutrients from soil.
What effect does acid rain have when it falls on rivers, lakes + streams?
Water becomes acidic which kills fish. Acidic water absorbs poisonous metal ions like aluminium which also kill fish.
What effect does acid rain have when it falls on limestone rocks, buildings + pavements?
Reacts with calcium carbonate in limestone so it corrodes.
What measures are used for prevent acid rain + how do they work?
Burn less fossil fuel - electricity used efficiently + renewable resources used.
Remove sulfur from fossil fuels - petrol + diesel.
Remove acidic gases from combustion products - scrubbers on chimney stacks which neutralise gases before they escape.
What process is used for making sulfuric acid?
What are the 4 main stages?
The Contact Process
Combustion of sulfur to form SO2, catalytic production of sulfur trioxide by mixing SO2 with more air to produce SO3.
Absorption in concentrated sulphuric acid by dissolving SO3 in H2SO4 to form oleum H2S2O7. Oleum mixed with water to produce concentrated sulphuric acid to form 2H2SO4.
The Contact Process: Temp Pressure Catalyst Why can't sulfur trioxide be added directly to water?
450c
2atm
Vanadium Oxide (V2O5)
Too exothermic, acidic mist formed which is difficult to contain.
What does sulfuric acid act as when it is concentrated?
Dehydrating agent,
What happens when sulfuric acid is reacted with sugar + equation?
Dehydrate/remove water from sugar leaving carbon.
C6H12O6 -> 6H2O + 6C
Darkens, sugar turns black, black column rises from beaker with steam, exothermic, burnt caramel smell.
What happens when sulfuric acid is reacted with hydrated CuSO4 + equation?
Removes water of crystallisation from blue crystals leaving white anhydrous copper sulfate + blue solution formed.
CuSO4.5H2O -> CuSO4 + 5H2O
Should you add acid to water or add water to acid?
Add acid to water.
What happens when sulfuric acid is reacted with calcium carbonate?
What if it was copper carbonate?
White solid disappears, colourless gas bubbles + heat.
Green powder disappears, colourless gas bubbles + heat.
