20 cm³ of 0.09 mol dm³ solution of tetraoxosuiphate (Vi) acid requires 30cm³ of sodium hydroxide solution for complete neutralization. The molar concentration of sodium hydroxide is [H = 1; S = 32; 0 = 16; Na = 23]

A. 0.03 mol dm³

B. 0.12 mol dm³

C. 0.27 mol dm³

D. 0.45 mol dm³

E. 0.90 mol dm³

The decreasing order of the oxidising power of the halogens is

A. Br>I>Cl>F

B. F>I>Cl>Br

C. F>Cl>Br>l

D. I>Br>Cl>F

E. Cl>Br>F>I

Which statement BEST describes the process of oxidation?

A. addition of hydrogen

B. loss of oxygen

C. decrease in oxidation number

D. loss of electrons

E. gain of elections.

Animal charcoal differs from wood charcoal in that it

A. has a dark colour

B. has a high carbon content

C. is a good absorbent

D. is crystalline.

E. is rich in phosphate content

The atomic number of iron is 56. The number of unpaired electrons in the Fe3+ ion is

A. 1

B. 2

C. 3

D. 4

E. 5

The use of sulphur to vulcanize rubber is mad to make it

A. blacker.

B. .

C. more elastic

D. tougher

E. softer.

Which element contains the greatest number of moles?

A. 8 g of Helium

B. 48 g of Carbon

C. 78 g of Potassium

D. 130g of Zinc

E. 216g of Sliver

The position of an element in the Periodic Table is determined by

A. its atomic radius.

B. its density.

C. its relative atomic mass.

D. the number of protons in its atom.

E. the number of neutrons in its atoms

What dose the following equation illustrate? \( ^{238}U_{92} → ^{234}Th_{90} + ^4 He_2 \)

A. Artificial radioactivity

B. nuclear fission

C. nuclear fusion

D. radio-decomposition

E. spontaneous disintegration