Question: What is the Chinese trivial name for the organic compound below?
A. 庚烷
B. 辛烷
C. 壬烷
D. 癸烷
Solution: D
4-propylheptane = isodecane
The molecular formula is still C_{10}H_{22} .
Question: Study the compound below:
(a) Notice the functional group(s). What will you call it as?
(b) What are the products when it is reacted with hot KMnO_4 / H^+ (aq)?
Solution:
(a) Alkyne (similar to cyanide)
(b) Carboxylic acid(aq) + CO_2 (g)
Question: Study the flow chart below:
(a) What reagent is missing for the last step?
(b) What solvent should be used to contain O_3 (g)?
Solution:
(a) H^+ / H_2O_2 (aq)
(b) CCl_4 (l)
Question: Alkyne can be converted to ketone by hydration.
(a) What reagents are commonly used?
(b) Name 2 alternative reagents.
Solution
(a) H_2O / H_2SO_4 (aq)
(b) HgSO_4 / H_2SO_4 (aq) or BH_3/ NaOH, H_2O_2 (aq)
Question: Study the flow chart below:
(a) What is the phase of the intermediate compound?
(b) What if Cu^+ or Ag^+ is used instead of Na?
Solution:
(a) Na (s) / NH_3 (l)
(b) Reddish-brown precipitate (for Cu^+) or Yellowish-white precipitate (for Ag^+) will be formed instead of colourless liquid
Solution:
HOX (e.g. Hydrobromous acid HOBr) (aq)
X = Br or Cl
Question: Study the reaction below:
(a) What is the mole ratio of alkyne:HOX?
(b) What is the by-product of the reaction?
Solution:
(a) 1:2
(b) water molecules
Question: Study the compound below:
(a) What is it called?
(b) How can it be prepared?
(c) What will happen if we dilute it?
Solution:
(a) Sulphonic acid
(b) Adding cold concentrated Sulphuric acid on an alkene
(c) Increment of protons will convert it to alkane.
Solution:
- Ozonolysis is redox reaction (i.e. involving electron transfer)
- Bond formation > Bond breakdown
