SCH 3U/4C - Nomenclature - Binary Compounds

This type of compound contains only two different elements in any ratio.  Since these compounds are ionic in nature, they typically contain a metal and a non-metal.

Rules for Writing a Name from a Formula

1.     Write down the name of the element with the lower electronegativity (usually a metal) first.

2.    Remove the ending on the name of the second element (usually a non-metal) and add “-ide” ending.

ex.(a)  KI          potassium iodide

     (b)  AlCl₃     aluminum chloride

     (c)  Na₂S     sodium sulfide

C4- carbide	N3- nitride	O2- oxide	F- fluoride
	P3- phosphide	S2- sulfide	Cl- chloride
	As3- arsenide	Se2- selenide	Br- bromide
		Te2- telluride	I- iodide
			At- astatide

Rules for Writing a Formula from a Name

1.     Write down symbols for the two elements, in the order they appear in the name.

2.    Place the valence of the first element above the first symbol.

3.    Place the valence of the second element above the second symbol.

4.    Use the ‘criss-cross’ rule and write the numbers as subscripts.

5.    Reduce the subscript numbers to the simplest ratio.

Ex.(a)  rubidium nitride               Rb¹   N³ ↝  Rb₃N

     (b)  magnesium phosphide    Mg²   P³ ↝  Mg₃P₂

     (c)  calcium oxide                   Ca²   O² ↝  Ca₂O₂  ↝  CaO

 

Want a bit more binary goodness?  Check out this video.

Homework

Give the correct formula for the following.

1.     sodium sulfide            

2.    calcium phosphide

3.    hydrogen iodide

4.    magnesium hydride

5.    barium oxide

6.    potassium oxide

7.    barium chloride

8.    aluminum oxide

9.    cadmium oxide

10.  francium oxide

11.  silver sulfide

12.  zinc chloride

13.  calcium iodide

14.  rubidium fluoride

15.  calcium chloride

16.  silver bromide

17.  beryllium fluoride

18.  lithium bromide

19.  potassium phosphide

20. aluminum hydride

21.  lithium oxide

22. barium bromide

23. aluminum carbide

24. strontium nitride

25. cadmium bromide

26. magnesium carbide

27. cesium nitride

28. zinc nitride

29. lithium selenide

30. beryllium telluride

Give the correct name for the following.

1.     NaCl       

2.    MgO

3.    CaO

4.    BBr₃

5.    MgS

6.    CaCl₂

7.    AlBr₃

8.    Rb₄C

9.    Al₂O₃

10.  Li₂O

11.  NaAt

12.  Be₃P₂

13.  BeF₂

14.  AlCl₃

15.  HCl

16.  SrCl₂

17.  Na₂O

18.  K₃N

19.  Li₃P

20. BaF₂

21.  MgI₂

22. K₂S

23. SrO

24. Al₂S₃

25. SrF₂

26. Ag₂S

27. RbI

28. Al₂O₃

29. MgO

30. KBr

 

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