seperate chemistry 1 Flashcards
transition metals
middle ones on table
transition metal properties
relativly hard, strong, shiny, mealleable. conduct electricity and heat
high melting points
high density
transition metals as catalysts
Iron in haber process
vanadium pentoxide for making sulfuric acid in contact process
transition metal compounds are very collourful\
Fe(II) is light greem and its compounds take that colour
what is the oxidisation of metals result in
corrosion
rusting
a redox reaction where metals lose electrons so it’s oxidised. oxygen gains electrons
rusting is the name for the corrosion of iron
experiment to show both ocygen and water is needed for iron to rust
Nail submerged in boiled water with oil on top to prevent oxygen in doesn’t rust.
Nail with calcium chloride to absorb water will not rust
air and water nail does
how to prevent rusting
Coating iron with a barrier.
painting
oiling or greasing
sacrificial protection
what is electroplating
appying a metal coat to an object
1) using electrolysis.
2) cathode is the object you are going to coat, anode the metal you are using for the coat. The electrolyte is a solution containing the metal ions of the metal you’re plating
titration
used to find out concentration
1) use a pipette, measure out a set volume of the alkali into a flask. Add a few drops of indicator (phenolphthalein or methyl orange)
2) fill a beurette with a standard solution of acid
3) use the beurette to add the acid to the alkali a bit at a time. Swirl the flask regularly.
4) The indicator changes colour when all alkai has been neutralised-
phenolphalien- pink in alkali to colourless
methyl orange- yellow in alkali to red
5) record volume of acid used
6) repeat a few times, making sure you get very similiar results and find the mean
how to calculate the concentration using titration results
concentration= number of moles(mol dm -cubed) / volume of solution (dm cubed)
percentage yield
(actual yield/theoretical yield)x100
atom economy
tells you what percentage of the mass of reactant has been converted into desired product
(total relative mass of desired/ total relative mass of all products) x 100
The haber process
N2 + 3H2 equlibrium 2NH3 + heat
1) hydrogen taken from natural gass and nitrogen from the air, in reaction vessel full of iron catalyst
when creating bonds is a example of
exothermic reaction
when breaking bonds is a example of
endothermic reaction
How do you prepare ammonium sulfate
through titration
1) set up beurette containing dilute sulfuric acid to drip into ammonia solution + indicator
2)Slowly add the acid into sample intil the yellow colour turns red, swirl flask, methyl orange changes when all alkali present is nuetralised.
3) to get pure ammonium sulfate crystals add the precise amount of acid you just found and repeat the titration but with no indicator.
4) to make them solid gently evaporate the solution and leave to crystallise
molar volume
(the volume occupied by one mole of a gas
unit dm3 mol-4)
molar volume= gas volume / number of moles
molar volume are the same under the same conditions
One mole of any gas alwayls occupies 24 dm3 at room temperature and pressre
volume= moles x 24
hydrogen-oxygen fuel cells
use hydrogen as fuel
the reaction between hydrogen and oxygen releases energy as they bond
advantages of hydrigen fuel cells
more efficient than power stations or batteries
Fuel cell ellectricity is generated directly from the reaction
no moving parts
no greenhouse gas, no nitrogen-oxides, no sulfaur dioxide, no carbon monoxide.
disadvantages of hydrogen fuel cells
is a gas so takes up a lot of space to store.
very explosive
