When steam is passed over red-hot carbon, the substances produced are

• A. Hydrogen and trioxocarbonate (IV) acid
• B. Hydrogen, oxygen and carbon (IV) oxide
• C. Hydrogen and carbon (II) oxide
• D. Hydrogen and carbon (IV) oxide

Sulphur (IV) oxide bleaches by

• A. Reduction
• B. Oxidation
• C. Hydration
• D. Adsorption

Sodium metal is always kept under oil because it

• A. Readily reacts with water
• B. Is reduced by atmospheric nitrogen
• C. Reacts vigorously on exposure to air
• D. Reacts with oxygen and carbon (IV) oxide

3Cu + pHNO₃ →3Cu(NO)₂ + 4H₂O + xNO In the equation above, the values of p and x respectively are

• A. 1 and 3
• B. 2 and 3
• C. 6 and 2
• D. 8 and 2

Carbon is tetravalent because

• A. The electrons in both the 2s and 2p orbitals are equivalent
• B. The electrons in all the orbitals of carbon are equivalent
• C. The 2s and 2p atomic orbitals hybridize
• D. All the atomic orbitals of carbon hybridize

A chemical reaction is always associated with

• A. an increase in the composition of one of the substance
• B. a change in the volume of the reactants
• C. a change in the nature of the reactants
• D. the formation of new substance

Alloys are best prepared by

• A. Electroplating
• B. Arc-welding
• C. Reducing and mixture of their metallic oxide
• D. Cooling a molten mixture of the metals

The mass of silver deposited when a current of 10a is passed through a solution of silver salt for 4830s is [Ag = 108, F = 96500 c mol-1]

• A. 108.0g
• B. 54.0g
• C. 27.0g
• D. 13.5gq

The property of chlorine which causes hydrogen chloride to be more ionic than the chlorine molecules is its

• A. electrovalency
• B. electron affinity
• C. electropositivity
• D. electronegativity

Aluminium hydroxide is used in the dyeing industry as a

• A. Salt
• B. Dye
• C. Mordant
• D. Dispersant