Question:
Draw the Lewis structure of a thiosulphate ion.
Question:
A student says that the oxidation number of S atom in H_2S_2O_8 is +7. Prove that he is on9.
Solution:
Note that the oxidation number of oxygen atoms in -O-O- peroxy bonding are always zero, so the maximum oxidation number of S atom is at most +6.
Solution:
Displacement Reaction (Redox)
Question:
In the Contact Process of 450^\circ C, why is Pt not used as catalyst?
Solution:
Because Pt is easily poisoned in high temperature, we use V_2O_5 instead.
Question:
What is the value of x in the bracket below?
SO_3 (g) + H_2O (l) \to H_2SO_4 (x)
Solution:
x=g (NOT x=l)
The product is a mist of acid.
Question:
Which of the following bonding is more stable?
- S-O
- S=O
Solution:
In terms of enthalpy:
- < 2.
The lower one is thermodynamically more stable, because it has longer bond length and smaller lone pair repulsion force.
Question:
Enumerate the isomers of SO_3.
Question:
Which one ion is the active ingredient of bleaching effect?
Solution:
H_3O^+ (aq)
Question:
What is the mode of the reaction below?
FeS (s) + HCl (aq)
Solution:
Ion exchange. Bad egg smell (H_2S (g))should be detected during the reaction.
Question:
Which one is more acidic: SO_2 or H_2S?
Solution:
H_2S is more acidic.
SO_2 is lone pair electrons donar, i.e. Lewis Base.
When they react, S(s) and water will be produced.