topic 5 separate chemistry 1 Flashcards
where are the transition metals on the periodic table
in the middle
what are the properties of transition metals
they are shiny, malleable, strong, hard, conduct heat and electricity, high densities, high mp apart from mercury which is liquid at room temp
what are transition metals good at
being catalysts e.g iron is used as a catalyst in the haber process
what are the compounds of transition metals like
colourful
how are alloys made
by adding another element to a metal
why are alloys stronger than pure metals
they have different size atoms making it harder for the layers of atoms to slide over each other
how is steel made
iron and carbon
how is bronze made and what are its uses
copper and tin, medals and statues
how is brass made and what are its uses
copper and zinc, door fittings and taps
what are aluminium alloys used for
to make aircrafts
how is magnalium made and what are its uses
aluminium and magnesium, fireworks
what are some methods used to prevent rusting
painting, oiling or greasing, sacrificial protection e.g galvanising
what is galvanising
a coat of zinc is put onto iron to prevent rusting, zinc is more reactive, so it’ll lose electrons and corrode in preference to iron
what is electroplating
coating the surface of a metal with another metal using electrolysis, cathode is the object you cot, anode is the bar of metal for the plating
what do you use titrations to find out
how much acid is needed to neutralise a given quantity of alkali
how do you calculate the concentration
number of moles/ volume of solution
how do you calculate percentage yield
actual yield/ theoretical yield X 100
why can you never get an 100% yield in real life :(
incomplete reaction, practical losses, unwanted reactions
how do you calculate atom economy
total Mr of desired products/ total Mr of all products X 100
what is atom economy
the % of reactants changed to useful products
what conditions are needed for the Haber process
pressure of 200 atmospheres, 450 degrees C
what are the three main essential elements in fertilisers
nitrogen, phosphorous and potassium
what are the advantages of ammonia fertilisers
you can control the compositions of chemicals in them as well as how much is made, soluble so all the chemicals can dissolve down into the soil to reach the plants
how do you make pure ammonium sulfate crystals in a lab
add a few drops of methyl orange indicator to the ammonia turning it yellow, add sulfuric acid until it changes to red, repeat without indicator to get a pure sample, evaporate solution and leave to crystallise
how do you calculate molar volume
gas volume/ number of moles
what molar volume do all RTP have
24
what fuel do hydrogen-oxygen cells use
hydrogen
what are the advantages of hydrogen fuel cells
efficient, electricity directly generated, few stages and no moving parts means less energy lost to heat and friction, only product is water
what are some disadvantages of hydrogen cells
hydrogen takes up a lot of space to store, explosive, uses electricity which is generated using fossil fuels
