Let's classify each of the given chemical reactions.
1. [tex]\( S + O_2 \rightarrow SO_2 \)[/tex]
This is a combination (or synthesis) reaction because two reactants, sulfur ([tex]\( S \)[/tex]) and oxygen ([tex]\( O_2 \)[/tex]), combine to form a single product, sulfur dioxide ([tex]\( SO_2 \)[/tex]).
2. [tex]\( CaCl_2 + 2 AgNO_3 \rightarrow Ca(NO_3)_2 + 2 AgCl \)[/tex]
This reaction is a double displacement (or double replacement) reaction. In this reaction, calcium chloride ([tex]\( CaCl_2 \)[/tex]) and silver nitrate ([tex]\( AgNO_3 \)[/tex]) exchange ions to form calcium nitrate ([tex]\( Ca(NO_3)_2 \)[/tex]) and silver chloride ([tex]\( AgCl \)[/tex]).
3. [tex]\( Zn + CuSO_4 \rightarrow Cu + ZnSO_4 \)[/tex]
This is a single displacement (or single replacement) reaction. Zinc ([tex]\( Zn \)[/tex]) displaces copper ([tex]\( Cu \)[/tex]) from copper sulfate ([tex]\( CuSO_4 \)[/tex]) to form zinc sulfate ([tex]\( ZnSO_4 \)[/tex]) and copper metal ([tex]\( Cu \)[/tex]).
4. [tex]\( 2 Na_2O \rightarrow 4 Na + O_2 \)[/tex]
This is a decomposition reaction. Sodium oxide ([tex]\( Na_2O \)[/tex]) decomposes into sodium ([tex]\( Na \)[/tex]) and oxygen ([tex]\( O_2 \)[/tex]).
5. [tex]\( 2H_2 + O_2 \rightarrow 2H_2O \)[/tex] (Note: assuming this was intended to be present and is a common example)
This is another combination (or synthesis) reaction because hydrogen ([tex]\( H_2 \)[/tex]) and oxygen ([tex]\( O_2 \)[/tex]) combine to form water ([tex]\( H_2O \)[/tex]).
To summarize:
1. [tex]\( S + O_2 \rightarrow SO_2 \)[/tex]: Combination reaction
2. [tex]\( CaCl_2 + 2 AgNO_3 \rightarrow Ca(NO_3)_2 + 2 AgCl \)[/tex]: Double displacement reaction
3. [tex]\( Zn + CuSO_4 \rightarrow Cu + ZnSO_4 \)[/tex]: Single displacement reaction
4. [tex]\( 2 Na_2O \rightarrow 4 Na + O_2 \)[/tex]: Decomposition reaction
These classifications help in understanding the nature and behavior of chemical reactions in different scenarios.
