what you need to revise more on Flashcards
(15 cards)
What is an alloy?
A mixture of a metal with one or more other elements (usually metals or carbon) to improve strength or resistance to corrosion.
Why is stainless steel better than pure iron?
It is stronger and resistant to corrosion, making it more durable for things like cutlery.
Why can some metals be extracted using carbon and others can’t?
Only metals below carbon in the reactivity series (like zinc) can be extracted by carbon. More reactive metals (like magnesium) need electrolysis.
How is limestone used in the blast furnace?
It decomposes to form calcium oxide, which reacts with impurities like silicon dioxide to form slag.
What is cracking and how is it done?
Cracking breaks long-chain hydrocarbons into shorter ones by heating and using a catalyst or high temperature.
Why is cracking important?
It produces useful fuels and alkenes that are used to make plastics.
What is a hydrocarbon?
A compound made only of hydrogen and carbon atoms.
What is polymerisation?
A process where many monomers join together to form a polymer (long-chain molecule).
Give two everyday uses of ethanol.
Fuel (blended with petrol) and solvent (used in perfumes, mouthwash, etc.).
Give one disadvantage of using emulsions in food.
Some people may have allergies or find the product less natural.
Why do substances at the top of the fractionating column have low boiling points?
They have small molecules that condense at cooler temperatures higher up the column.
What is thermal decomposition?
The breakdown of a compound using heat, producing simpler substances.
What materials are added at the top of the blast furnace?
Iron ore, coke, and limestone.
How is crude oil separated into fractions?
Heated and vaporised crude oil enters a fractionating column, where substances condense at different levels depending on their boiling points.
Why is hydrogen similar to Group 1 elements?
Hydrogen has 1 electron in its outer shell and forms +1 ions, just like Group 1 metals.
