Ch 11 Compounds, Mixtures and Solutions Flashcards
what are compounds
substances made by joining together two or more elements
what are bonds
strong forces that chemically join together the elements in a compound
what is a mixture
a material containing two or more elements or compounds that are in close co tact and are mixed e.g. seawater is a mixture of salts and water
what are molecules
groups of two or more atoms bonded together e.g. water and carbon dioxide
what is the characteristic of pure substances
they contain only atoms or molecules of that substance e.g. oxygen
how do you test the purity of a substance
measure the physical properties: melting point
boiling point
density
what is the solute
the substance that dissolves
what is the solvent
the substance that the solute dissolved into
what is a solution
when a solute dissolves into a solvent it forms a solution
what does soluble mean
solids that dissolve are soluble
what does insoluble mean
solids that don’t dissolve are insoluble
what is suspension
when a solids doesn’t dissolve and settles to the bottom of the liquid or floats around
what is solubility
a measure of how much solute can dissolve in a fixed volume of solvent to make a saturated solution
what is concentration
how much solute is dissolved in the solvent
what is a dilute solution
it contains a small quantity of solute in a large quantity of solvent
what is a concentrated solution
it contains a large quantity of solute in a small quantity of solvent
what is a saturated solution
it contains as much solute as possible at a given temperature
what is crystallization
the formation of crystals ( cooling a saturated solution )
in what ways can separation of mixture be done
- filtration
- chromatography
- evaporation
- distillation
- magnetism
- separating immiscible liquids
describe the process of filtration
it is used to separate insoluble solids from liquids.
you use filter paper and put the liquid through it. the insoluble solids should get stuck in the paper and the liquid should go through
describe chromatography
it is used to separate mixture of substances that are in solution
the different substances are carried up a piece of chromatography paper by the solvent at different rates
describe evaporation
it is used to separate a liquid and a soluble solid
the solvent is evaporated and the solute is left behind in the evaporating dish
describe distillation
it is used to separate a liquid and a soluble solid when you want to keep the solvent
the liquid with the lowest boiling point evaporated first . a liebig condenser is used during distillation
describe magnetism
used to separate if one of the substances in the mixture is magnetic
the substance will be attracted the the magnet
explain separating immiscible liquids
the less dense liquid will float on top of the other liquid. a separating funnel can be used to separate immiscible liquids
how does fractional distillation
crude oil is separated by fractional distillation
the oil is heated and turns to a gas. the gas is out in a large tower and it cools as it rises up the tower. substances with high boiling points turn to liquid at the bottom of the tower and substances with low boiling points turn liquid at the top
what are monomers
raw materials separated from crude oil by fractional distillation
what is polymerisation
when small repeating units called monomers bond together to form larger chains called polymers
what does non- biodegradable mean
bacteria cannot break them down
explain the process of fracking
fracking involves drilling into the earth and injecting a mixture of water,sand, and chemicals into the rick at high pressure, which releases the gas trapped in the rock.
what are three advantages of fracking
- provides access to oil and gas
- releases methane which is the least polluting of all fossil fuels
- provides fuel source
what are three disadvantages of fracking
- large amount of water are needed
- may result in small earthquakes
- natural gas is a non renewable form of energy
