triple chem content Flashcards
(56 cards)
Physical properties transition elements
good conductors of thermal energy/electricity
hard and strong
high density
high melting points(except mercury-liquid at room temp) (higher than alkali metals)
chemical properties transition elements
less reactive than group 1
do not react easily with water/o2
eg. copper has to be jeated to react with o2
corrode very slowly
colours of transition metal compounds:
copper(2) sulfate
nickel(2) carbonate
chromium(3) oxide
manganese(2) chloride
copper(2) sulfate—> blue
nickel(2) carbonate—>pale green
chromium(3) oxide—>dark green
manganese(2) chloride—>pale pink
transition metal used as a catalyst in the haber process
Iron
coarse particles are also known as…
PM10
Coarse particles-diameter
between 110^-5m and 2.510^-6m
fine particles are also called…
PM2.5
fine particles diameter
100-2500 nanometers
110^-7m and 2.510^-6m
nano particles diameter
between 1-100 nanometers
what happens to the particles surface area to volume ratio when the size is decreased by 10
increases by 10 times
benifits of nanoparticles having a huge surface area to volume ratio
a much smller quantity of nanoparticles is needed
risks of nano particles
violent explosions from sparks as they have large surface areas
unpredictable effects on cells
environment
more research required
how much volume does one mole of gas occupate at room temp//pressure
24 dm cubed
what is room temp
20C
What is room preassure
1 atmosphere
volume of gas formula
volume(dm cubed)=number of moles*24
reaction for titration
sulfuric acid+sodium hydroxide—>sodium sulfate+water
neutralisation reaction
what do titrations tell us
if we have a certain volume of sodium hydroxide and we know the concentration+
we know the volume of sulfuric acid needed to neutralise the alkali we can use this to calculate the concentration of the acid
describe process of titration
1.use pipette to transfer 25 cm cubed of sodium hydroxide into a conical flask (allow liquid to drain out of pippette dont force it out bcz wrong volume will be given… use pipette filler)
2. add 5 drops of indicator… methyl orange or phenolphthalein into the alkali flask
3. place flask on white tile to see colour change clearly
4. fill a burette with sulfuric acid
5. add acid to the alkali until solution is neutral
once colour change is detected allow acid to be added drop by drop
swirllll
6. read volume of acid added from the burette at the meniscus
fuel cells negative electrode equation
2H2—->4H(+)+4e(-)
fuel cells positive electrode equation
O2+4H(+)+4e(-)—->2H2O
Overall fuel cell equation
2H2+O2—>2H2O
What happens to hydrogen in fuel cells
Hydrogen
general formula for alkenes
CnH2n
