OCR Gateway GCSE Chemistry A Global challenges (C6) overview quiz quiz

Nitrogen from natural gas and hydrogen from the air

Both from electrolysis of water

Nitrogen from the air and hydrogen from natural gas

Both from crude oil

A lower temperature would increase the rate of the reaction far too much to control safely

A lower temperature would make the iron catalyst stop working permanently and never recover

The forward reaction is endothermic, so using a higher temperature would only lower the equilibrium yield even further

The forward reaction is exothermic, so a lower temperature raises the yield but makes the reaction too slow

Nitrogen, phosphorus and potassium

Nitrogen, potassium and carbon, plus a little iron

Sodium, phosphorus and potassium, plus some sulfur

Nitrogen, phosphorus and calcium, plus a little zinc

Buying the product, using it, cleaning it and then selling it on second-hand

Obtaining raw materials, manufacture, use and disposal

Mining the materials, packaging, advertising and finally recycling the waste

Designing the product, manufacturing it, marketing it and working out the profit

It always uses exact, precisely measured data for every single stage of the assessment

It only ever considers the manufacturing stage and ignores all of the other stages

Some impacts require value judgements, so it can be biased

It is decided entirely by the government with no input from the company at all

Flammability

Volatility

How easily the fraction flows

Boiling point

A shorter alkane and an alkene

Two shorter-chain alkanes only, with no alkene formed at all

An acid and a salt, in the same way as a neutralisation reaction

Carbon dioxide and water, just as in the complete combustion of a fuel

About 80 percent oxygen and 20 percent nitrogen

About 80 percent nitrogen and 20 percent oxygen

About 80 percent carbon dioxide and 20 percent oxygen

About 50 percent nitrogen and 50 percent oxygen

They absorb the incoming short-wave radiation from the Sun before it ever reaches the surface of the Earth

They reflect all of the incoming radiation straight back out into space before it can warm anything

They absorb outgoing long-wave (infrared) radiation from the Earth and re-emit some back

They release stored heat directly by reacting chemically with the oxygen in the air

It causes acid rain by dissolving in the water droplets found high up in the clouds

It is a powerful greenhouse gas that traps heat and warms the surface of the Earth

It dissolves limestone buildings and statues over time by reacting with the stone

It is toxic and reduces the amount of oxygen the blood can carry

Sulfur dioxide and oxides of nitrogen

Carbon monoxide and carbon dioxide from the burning of fossil fuels

Oxygen and nitrogen, the two main gases that make up the atmosphere

Water vapour and methane released from farms and from decaying matter

Sea water has no microbes in it at all, so it only ever needs a little salt adding

Sea water contains dissolved salts that filtration cannot remove

Fresh water actually contains far more dissolved salt in it than sea water does

Reverse osmosis adds extra salt to the water to make it safer for people to drink

Bacteria are used to produce a leachate solution containing dissolved copper compounds

The ore is heated very strongly with carbon in a furnace in order to reduce and release the copper metal

Plants absorb copper compounds, are harvested and burned, and copper is extracted from the ash

Copper is simply filtered directly out of the soil using a fine mesh and then collected