SECTION A Part 2 (A5,A6 and A7)

When aqueous silver nitrate is added to an aqueous solution of magnesium chloride, a white precipitate forms. The ionic equation for the formation of this precipitate is:

• Mg⁺ (aq) + NO₃^-(aq) = MgNO₃ (s)

• Ag²⁺(aq) + 2Cl^-(aq) = AgCl₂(s)

• Mg²⁺(aq) + 2NO₃^-(aq) = Mg(NO₃)₂(s)

• Ag⁺(aq) + Cl^-(aq) = AgCl(s)

The high melting point of ionic compounds may be due to the

• arrangement of ions

• large number of ions

• attraction among ions

• movement of ions

Which of the following statements about chemical reactions is NOT correct?

• Energy given out when bonds break and taken in when bonds form

• Chemical reactions involve the making and breaking bonds

• Endothermic reactions take energy from surroundings

• Exothermic reactions give energy to the surroundings.

Graphite can be used as a lubricant because of

• strong attraction between the hexagonal layers of carbon atoms

• weak attraction between the hexagonal layers of carbon atoms

• the loose electrons which can move throughout the lattice

• strong attraction within the hexagonal layers of carbon atoms

Which of the following compounds does NOT consist of individual molecules?

• ethane

• ethanol

• hydrogen chloride

• sodium chloride

Which of the following salts are soluble in water?  

I. ammonium carbonate.    

II. barium sulfate.    

 III. lead nitrate.

• I and II only

• I and III only

• II and III only

• I, II and III

Which of the following statements would be correct if diamond and graphite are allotropes?  

I. Both can be represented by the symbol C.    

II. Both have a relative atomic mass equal to that of carbon.

  III. They have similar physical properties.

• I and II only

• I and III only

• II and III only

• I, II and III

Which of the following quantities of acid can exactly neutralise 40cm³ of 2 moldm^-3 sodium hydroxide?      

 I. 10 cm³ of 2.0moldm^-3 hydrochloric acid    

II. 10 cm³ of 4.0 moldm^-3 sulfuric acid.      

III. 20 cm³ of 4.0 moldm^-3 nitric acid.

• I only

• II only

• II and III only

• I and II only

Which of the following quantities of acid can exactly neutralise 20cm³ of 2 moldm^-3 sodium hydroxide?        

I. 10 cm3 of 4.0moldm^-3 hydrochloric acid    

II. 10 cm3 of 2.0 moldm^-3 sulfuric acid.      

III. 20 cm3 of 4.0 moldm^-3 nitric acid.

• I only

• II only

• II and III only

• I and II only

Which TWO of the following statements about covalent compound are true?    

  I. They are mainly solid.      

II. They usually have low melting and boiling points.      

     III. They are usually insoluble in water.      

IV. They contain only ions.

• I and III

• I and IV

• II and III

• II and IV