Cosas Que Tengo Que Saber Flashcards
State what is meant by the term electrolysis?
Breakdown of an ionic compound molten or dissolved using electricity
State what is meant by the term equilibrium?
When the rate of both the forward and backwards reaction are equal and the reaction is happening at a constant concentration
Give the name used to describe a “family” of similar compounds with the same general formula, similar chemical properties and the same functional group.
Hermologous series
State the colour change observed when propane is added to aqueous bromine
From orange to colourless
Describe a test for oxygen
Test: glowing splint
Observations: It relights
Describe a test for hydrogen
Test: put a lit splint
Observations: it will make a squeaky pop
Test for chlorine gas
Test: damp blue litmus paper
Observations: bleaches
Test for carbon dioxide
Test: limewater
Observations: turns cloudy white and milky
Test for ammonia
Test: damp red litmus paper
Observations: turns blue
General formula of carboxylic acids
CnH2n+1COOH
General formula of alcohols
CnH2n+1OH
General formula of alkenes
CnH2n
General formula of alkanes
CnH2n+2
Test for sulphur dioxide
Turns acidified aqueous potassium manganate from purple to colourless
State the meaning of the term base
Proton acceptor
State the meaning for the term acid
Proton donor
State what is meant by the term catalyst
Something that speed up the rate of reaction without being used up
State general characteristics of hermologous series
- general formula
- chemical properties
- functional group
Ionic bond
Electrostatic attraction between oppositely charged ions
Avogadros number
6.02 x 10^23
Mass=
Mr x mol
Percentage yield=
Actual yield over theoretical yield x 100
Number of moles (vol, conc)
volume of solution x Concentration (in mol/dm^3)
Volume of a gas (dm^3) =
Moles of gas x 24
Percentage purity =
Pure yield/ total impure yield x100
Percentage composition by mass =
Mr of element that is asked/ mr of total compound x100
Electroplating:
Anode: metal
Cathode: object
Electrolyte: contains metal ions of the metal you are plating (eg silver nitrate)
Exothermic reactions
More energy is needed to make the bonds in the products than to break the bonds in the reactants
Endothermic
More energy is needed to break the bonds in the reactants than is to make the bonds in the products
Activation energy
The minimum amount of energy required for a reaction to occur
Redox is
When oxidation and reduction occur at the same time
Reducing agents
Cause other substances to be reduced, therefore they themselves are oxidised
Oxidising agents
Cause other substances to oxidise, therefore they themselves are reduced
Group 1 metals are called
Alkali metals
Group 7 elements are called
Halogens
Fluorine is a
Yellow gas
Chlorine is a
Green gas
Bromine is a
Red/brown liquid
Iodine is a
Grey solid
Sublimation
When a solid turns directly into a gas
Where does carbon dioxide come from
Complete combustion of fuels (plentiful O2)
Where does carbon monoxide come from
Incomplete combustion of fuels (insufficient O2)
Where does methane come from
- waste gases from digestion of animals
- decomposition of vegetation
Where do oxides of nitrogen come from
-high temp in car engines cause O2 and N2 to react
Where does sulfur dioxide come from
Sulfur impurities in crude oil
Consequences of carbon dioxide
-enhanced greenhouse effect -> global warming -> climate change + extinction of species
Consequences of methane
-enhanced greenhouse effect -> global warming -> climate change + extinction of species
Consequences of carbon monoxide
Toxic gas
-> combines irreversibly with red blood cells
Consequences of oxides of nitrogen
-acid rain
-respiratory problems
-photochemical smog
Consequences of sulfur dioxide
-acid rain
Consequences of particulates
- respiratory problems + cancer
Use of alcohols
-alcoholic drinks
-perfumes (they are good solvents)
-fuels
Rf value=
Distance traveled by component/ distance traveled by solvent
Define a Redox reaction
Where oxidation and reduction occur at the same time
State how a student knows that a suitable number of results have been obtained
When he has obtained at least 2 results that are within 0.2 or less
State observations that indicate that ……………. Is in excess
- no more ……………. Can dissolve
- no more bubbles
Give a reason why the rate of reaction increases when using powder
Because tha powder has a larger surface area, therefore more area is able to react at the same time so there are more collisions per unit time so there is an increase in rate of reaction
State differences in the physical properties of group 1 elements and transition metals
- group 1 elements have lower melting points
-group 1 metals are softer
-transition metals are denser
Explain why chlorine does not react with aqueous sodium fluoride
Because fluorine is more reactive than chlorine
Suggest why …………. Might be done in an atmosphere of argon and not in air.
Reacts with oxygen and argon is inert
Explain how this chemical equation shows that ……………. Is acting as a reducing agent
………………. is oxidised
Reaction of metal and water
Metal + water -> metal hydroxide +hydrogen
