Discussion (Chemistry)
Daniel Koh
Have some questions on hand for discussion. Do take note of these as
it came out in past year papers.
Q1. Give the ion-electron equations for the electrode reactions in the
electrolysis of aqueous sulphuric acid using inert electrodes.
[Particularly, this question is very rare compared to ones found in
other years. Do not really have it in pre lim papers. Nevertheless, it
is important. I was shock to find out that the answer is very simple.]
Q2. Under which conditions do real gases obey the ideal gas equation
most closely?
1. High Temp and High pressures
2. High temp and low pressures
3. room temp and high pressures
4. room temp and pressure
[Overestimated my preparation. Didn't expect such question would come
out. Take note!]
Q3. Sodium azide, NaN3, is made for use in car 'air bags'. When this
compound is heated to 300*C, it rapidly decomposes into its elements.
Which volume of gas, at room temperature and pressure, would be
produced by the decomposition of one mole of sodium azide?
1. 24dm^3
2. 36dm^3
3. 48dm^3
4. 72dm^3
[* - degree]
Q4. The current of 8A is passed for 100 min through molten aluminium
oxide, using inert electrodes. What is the approximate volume of gas
liberated, measured at s.t.p.?
1. 2.8dm^3
2. 8.4dm^3
3. 11.2dm^3
4. 22.4dm^3
Q5. After the reduction of nitrobenzene to phenylamine, using tin and
concentrated hydrochloric acid, an excess of sodium hydroxide is
added. What is the purpose of the sodium hydroxide?
1. to dry the product
2. to liberate phenylamine
3. to lower the boiling point for subsequent distillation
4. to precipitate tin (II) hydroxide
Q6. Is it that the reactant compound that undergoes disproportionation
cannot function itself as an oxidising agent?
Q7. What can affect the magnitude of the equilibrium constant, Kp, of
a reversible gaseous reaction?
1. temperature
2. pressure
3. catalysts
Let's make this online portal an active one, so that we can learn from
one another. Gone are the days when asian fought to survive. Embrace
the European mindset; forgo the old tradition of translating skills to
our fellow followers or classmates 99.999% of what we know in fear of
usurping our seats. Hit the books and let us work together in this on-
going race.
Daniel