chem paper 2 Flashcards
Suggest one possible risk associated with using nanoparticles.
long term effects not known/ may build up in {living things/
water supplies/ environment}
State one property of titanium dioxide nanoparticles that make them suitable
for use in sunscreens
colourless / absorbs UV / non-toxic / large SA : vol ratio
Name a piece of apparatus that would be better to measure the volume of gas
produced, instead of the 250cm3
measuring cylinder.
100 cm3 measuring cylinder/ (gas) syringe (1)
* which has smaller gradations / higher resolution (1)
The student measured the volume of gas for 10 minutes.
State why the measurements could have been stopped at 9 minutes.
volumes were {constant / stopped rising}
OR
graph was {flat/plateaued/ levelled off}
Explain why the rate of reaction increases when the concentration of acid is
increased.
more particles->more frequent collisions
Explain, using Figure 5, why helium is inert.
it has a full outer shell so does not lose/gain/transfer/share electrons
State one property of helium, apart from it being inert, that makes it suitable
for filling balloons.
it is less dense than air
red flame?
lithium
Give two ways in which the data in Figure 8 shows that the diesel engine is
more damaging to the environment than the petrol engine.
Diesel engines give off more
viscosity increases as
molecules get larger
when you break a bond, energy is….
absorbed
Give the name of the carbon-containing product formed when propanol undergoes dehydration.
propene
why a blue, roaring flame
very hot flame
what is sedimentation
impurities in water settle to bottom of container
why is waste water filtered?
to remove insoluble substances
