Chrmistry Paper 2 Flashcards
What is cracking?
Cracking is taking longer chain hydrocarbons molecules and breaking them down into smaller more useful molecules.
What is the general formula for alkenes?
CnH2n
What is the general formula for alkanes?
CnH2n+2
What are the first 5 alkanes?
Methane, ethane, propane, butane and pentane.
What is crude oil?
Crude oil is a mixture.
How is crude oil formed?
Formed over millions and millions of years from the remains of Dead Sea creatures.
What is a finite resource?
A resource in limited quantities.
How can you identify an impure substance?
An impure substance has a lower melting point and melts over a temperature change.
What is the common trend in impure substances?
Impurities tend to lower the melting point and increase the boiling point.
What is a pure substance?
A single element or compound not mixed with any other substances.
What are the requirements for cracking?
Cracking requires high temperatures and a catalyst.
What is membrane distillation?
Salt water is forced through the membrane sheets at high pressure. Membrane sheets are designed to catch salt ions/ bigger molecules. Water can pass through the membrane but sodium and chlorine can’t.
What is desalination?
A process that removes minerals from saline water.
What is distillation?
The process if separation of a mixture through selective evaporation. But it requires a lot of energy and is expensive.
What is drinking water?
Also known as potable water is water that is safe to drink or to use in food preparation without risk of acute or chronic health impacts.