SNC 2P - Chemistry - Stock Naming System

Some elements have more than one valence they may use when bonding.  The Stock system uses Roman numerals to indicate which valence the element is using in a particular compound.  


Rules for Writing a Name from a Formula

1.     Write down the name of the first element.  This is the element that may have more than one valence.

2.    Include a Roman numeral to represent the valence of the first element (reverse the ‘criss-cross’ to determine the valence).

3.    Remove the ending on the name of the second element and add the “-ide” ending.

ex.(a)  FeCl₂     Fe²   Cl¹       iron (II) chloride

     (b)  FeCl₃     Fe³   Cl¹       iron (III) chloride

    (c)  SnO      Sn¹   O¹        tin (II) oxide          *this is a special case – reversing the criss-cross tells us that the valence of oxide is 1, which is not possible – the valence of oxide must be 2.  This formula must have been reduced to a simplest ratio.  Therefore, reversing the criss-cross should give us:  Sn²   O², giving us the name tin (II) oxide

         

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 (Roman numeral).

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)  copper (II) oxide            Cu²   O²  ↝  Cu₂O₂  ↝  CuO

     (b)  chromium (III) sulfide     Cr³   S²  ↝   Cr₂S₃

Need a bit more Stock system in your life?  Check out this video.

Homework

Give the correct formula for the following.  Do as many questions as it takes to get 10 correct.

1.    copper (I) oxide         

2.    copper (II) oxide

3.    tin (IV) chloride

4.    mercury (II) bromide

5.    iron (III) fluoride

6.    chromium (III) oxide

7.    chromium (II) oxide

8.    iron (II) chloride

9.    sulfur (VI) fluoride

10.  arsenic (III) iodide

11.  lead (II) oxide

12.  cobalt (II) nitride

13.  cobalt (III) sulfide

14.  phosphorus (III) chloride

15.  phosphorus (V) iodide

16.  manganese (III) oxide

17.  nickel (II) oxide

18.  cobalt (III) fluoride

19.  gold (I) bromide

20. lead (II) sulfide

21.  iron (III) phosphide

22. 

23. mercury (I) sulfide

24. tin (II) phosphide

25. nitrogen (V) sulfide

26. tin (IV) oxide

27. copper (I) iodide

28. phosphorus (III) chloride

29. sulfur (VI) oxide

30. silicon (IV) chloride

Give the correct name for the following.  Do as many questions as it takes to get 10 correct.

1.    SnF₂       

2.    SnF₄

3.    Cu₂S

4.    CuS

5.    Cr₂O₃

6.    SnS

7.    Fe₂O₃

8.    HgCl₂

9.    CoCl₃

10.  Co₃N₂

11.  PbO

12.  As₂S₃

13.  PCl₃

14.  P₂O₅

15.  PbCl₄

16.  Cu₂O

17.  HgI

18.  Fe₂S₃

19.  

20. NCl₃

21.  As₂S₅

22. Au₂O₃

23. NiO

24. SnF₄

25. MnO

26. PCl₅

27. Cu₃N₂

28. Cu₃N

29. PbS 

30. Ni₂O₃

Answer Keys:

 

SNC 2P - Chemistry - 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.  Do as many questions as it takes to get 10 correct.

1.    sodium sulfide            

2.    calcium phosphide

3.    hydrogen iodide

4.    

5.    barium oxide

6.    potassium oxide

7.    barium chloride

8.    aluminum oxide

9.   

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. 

21.  lithium oxide

22. barium bromide

23. aluminum carbide

24. strontium nitride

25. 

26. magnesium carbide

27. 

28. zinc nitride

29. 

30. 

Give the correct name for the following.  Do as many questions as it takes to get 10 correct.

1.    NaCl       

2.    MgO

3.    CaO

4.    BBr₃

5.    MgS

6.    CaCl₂

7.    AlBr₃

8.    Rb₄C

9.    Al₂O₃

10.  Li₂O

11.  

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

 

Answer Keys: