Chemical reaction

Which general formula shows decomposition reaction?

What is two or more substances that are together in the same place but their atoms are not chemically bonded.

What type of reaction is the following:
 $2H_2+O_2->2H_2O$  

What type of reaction is the following:
 $BaCl_2+2KI\ ->\ 2KCl\ +\ BaI_2$  

What type of reaction is the following:
 $2KI\ ->\ 2K\ +\ I_2$  

What type of reaction is the following:
 $2NaHCO_3->\ Na_2CO_3+CO_2+H_2O$  

What type of reaction is the following:
 $Zn\ +\ 2HCl\ ->\ ZnCl_2+H_2$ 

The rate of a reaction increases as temperature__________________.