CIE iGCSE Co-Ordinated Science C2.4 Ions and ionic bonds Exam Style Questions Paper 3
Question
(a) Sodium and chlorine are elements.
Sodium chloride is a compound.
Describe what is meant by an element and a compound.
element …………………………………………………………………………………………………………………….
…………………………………………………………………………………………………………………………………
compound …………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(b) Sodium reacts with chlorine to make sodium chloride.
Balance the symbol equation for this reaction.
………Na + Cl$_{2}$ ………NaCl
(c) When sodium reacts with chlorine, sodium atoms become sodium ions and chlorine atoms become chloride ions.
The electron configuration of a sodium atom is 2.8.1.
The electron configuration of a chlorine atom is 2.8.7.
State the electron configuration of a sodium ion and a chloride ion.
sodium ion ………………………………………..
chloride ion ………………………………………..
(d) Describe the difference in the solubility in water of an ionic compound compared with a covalent compound.
…………………………………………………………………………………………………………………………………
…………………………………………………………………………………………………………………………………
(e) Sodium chloride contains chloride ions.
Describe the test for chloride ions and state the observation for a positive result.
test …………………………………………………………………………………………………………………………..
observation ……………………………………………………………………………………………………………….
(f) Fig. 11.1 shows the electrolysis of concentrated aqueous sodium chloride.
Complete the sentences about the electrolysis of concentrated aqueous sodium chloride.
Electrolysis is defined as the breakdown of an ionic compound when
………………………………. or in aqueous solution by the passage of ……………………………….
The gas released at the negative electrode is ………………………………. and the gas
released at the positive electrode is ………………………………. .
▶️Answer/Explanation
Ans: 11(a) element – contains only one type of atom ;
compound – contains two or more elements (chemically combined) ;
11(b) 2Na + Cl$_{2}$ → 2NaCl ;
11(c) sodium ion 2.8 ;
chloride ion 2.8.8 ;
11(d) solubility of ionic compound is greater ;
11(e) add acidified aqueous silver nitrate ;
white precipitate ;
11(f) molten ;
electricity ;
hydrogen ;
chlorine ;