1. An English Physicist Rayleigh performed a series of
experiments to determine with great accuracy, how much a litre of
N2 weighs (eg. its density)
So he proceeded to remove the O2, CO2 and water vapour from air
to get pure N2 before weighing it.
To check his results he used another method to obtain N2 instead
of from air. He extracted N2 from ammonia, and purified it
according to all the rules and weighed it. A litre of N2 from air
weighted 1.2572g while that from ammonia weighed 1.2560g.
Suggest an explanation why the N2 from air was heavier than the
N2 obtained from NH3.(assuming it was not due to experimental
error)
2. A student made crystals of sodium sulphate from NaOH and
dilte H2SO4 from the following procedures.
Some NaOH solution was placed in an evaporating dish and a few
drops of litmus solution added. The dilte H2SO4 was then added
slowly from a measuring cylinder until the litmus solution changed
colour. The solution in the evaporating dish was then heated
strongled untill all the water has evaporated.
State the colour change of litmus solution (the same as litmus
paper???)
If yes then my guess is from blue to red. Hahah!
;D