Chemistry Past Questions and Answers

In which of the following reactions can the oxidation number of the nitrogen be said to have increased?

A 2NO_(g) + O_2(g) â†’ 2NO_2(g)
B NO_(g) + Cl_2(g) → NOCl_2(l)
C FeSO_4(aq) + NO_(g) â†’ Fe(NO)SO_4(s)
D NO_(g) + Br_2(l) â†’ NOBr_2(l)

Question 7:

2H₂ + O₂2 â†’ H₂+O Î”H = -571kJ
In the equation above, how much heat will be liberated if 12.0g of hydrogen is burnt in excess oxygen?

A -1142 kJ
B -571 kJ
C +1142 kJ
D -1713 kJ

Question 8:

A concentrated solution containing H⁺, Cu²⁺, OH^- and Cl^- was electrolyzed using platinum electrodes.
The ion that will be discharged at the cathode is

A Cu²⁺
B Cl^-
C H⁺
D OH^-

Question 9:

When sulphur (IV) oxide is passed into a solution of sodium hydroxide for a long time, it eventually produces a solution of

A NaHSO₄
B Na₂SO₃
C NaHSO₃
D Na₂SO₄

Question 10:

What is the correct IUPAC name for NO\(_{2} ^{-}\)?

A Dioxonitrate (IV) ion
B Trioxonitrate (III) ion
C Trioxonitrate (IV) ion
D Dioxonitrate (III) ion