Which group does calcium belong to in the periodic table?

• A. Alkaline earth metals
• B. Halogens
• C. Alkali metals
• D. Noble gases

When air is passed through a heated tube containing finely divided copper, the component that is absorbed in the process is

• A. carbon (IV) oxide
• B. nitrogen
• C. oxygen
• D. water vapour

Powdered marble reacts faster with hydrochloric acid solution than the granular form because the powdered form has

• A. more molecules
• B. more atoms
• C. larger surface area
• D. relatively large mass

(a) State the main ore of tin.

(b) Write an equation for the reaction involved in the smelting of purified tin ore

(c) List two alloys of tin

Which of the following types of alkanols undergo oxidation to produce alkanoic acids? 1. Primary alkanols 11. Secondary alkanols 111. Tertiary alkanols

• A. I, II and III
• B. l and ll only
• C. ll only
• D. l only

Given that for the reaction. N2(g) + 3H2(g) ⇌ 2NH3(g) if enthalphy change = -92kJ. What is the enthalpy of formation of ammonia from its elements?

• A. -46KJ mol^-1
• B. -184KJmol^-1
• C. -92KJmol^-1
• D. 184KJmol^-1

A chemical equilibrium is established when

• A) concentration of the reactants and products are equal
• B) reactants in the system stop forming the products
• C) concentrations of the reactants and products remain unchanged
• D) reactants in the system are completely transformed to products

How much heat will be liberated if 8g of hydrogen burns in excess oxygen according to the following equation? 2H₂+ O₂→ 2H₂O, ΔH = -571.7KJ (H = 1)

• A. 1.42.9KJ
• B. 571.7KJ
• C. 1143.4KJ
• D. 285.9KJ

Which of the following explains why trioxonitrate (V) acid is not used for preparing hydrogen from metals?

• A. it is volatile
• B. it is strongly oxidizing
• C. it forms a layer of oxide on the metal
• D. trioxonitrate (V) salts are soluble in water

What will happen if an aluminium spoon is used to stir a solution of iron (II) trioxonitrates (V)?

• A. The spoon will be oxidized while the iron (II) ions will be reduced to the metal
• B. The spoon will increase in size
• C. The spoon will be reduced while the iron (II) ions will be oxidized
• D. The spoon will be reduced