Which metal is extracted from bauxite?

A. aluminium

B. calcium

C. copper

D. magnesium

E. tin

Which separation technique is routinely applied in the petroleum industry?

A. chromatography

B. distillation

C. evaporation

D. fractional crystallization

E. fractional distillation

Small amounts of compounds of transition metals are sometimes added to glass during manufacture in order to make the glass

A. acquire certain colours

B. easier to melt

C. easier to mould

D. little brittle

E. more transparent

The pH of water is 7.

What is the pH of orange juice?

A. 7

B. above 10

C. below 2

D. between 5.5 and 6.5

E. between 7.5 and 8.5

Chlorine displaces bromine from aqueous potassium bromide because

A. bromine is a liquid at room temperature

B. bromine is weakly acidic.

C. bromine has a greater atomic radius than chlorine

D. chlorine is a stronger oxidising agent than bromine.

E. the density of chlorine is less than the density of bromine.

What is the change in the oxidation number of phosphorus in the following reaction?

4P(s) + 5O₂(ag) → 2P₂O₅(s)

A. 0 to 2

B. 0 to 5

C. 4 to 2

D. 4 to 5

E. 4 to 10

In the reaction 2H₂S(g) + SO₂(g) → 2H₂SO(I)+3S(s)SO₂is acting as _agent

A. a bleaching

B. a dehydrating

C. an oxidizing

D. a precipitating

E. a reducing

What is the number of moles of NaHCO₃in 250cm³ of its solution if the solution contains 8.4 g of NaHCO₃ in 1 dm³ of the solution. [Na = 23, 0 = 16, C = 12, H = 1)

A. 1

B. 0.25

C. 0.05

D. 0.025

E. 0.01