classify the following compounds as ionic and covalent. CH4 ,CCl4 ,HCl , NaCl ,NH3 ,CaO ,H2O , Br2 ,C2H5OH , CH3OCH2CH3 ,Co ,CH2CH2 ,MgSO4 ,C2H2 , H2SO4, CH3COONa ,CO2 ,H2 , KBr ,O2 ,NaOH.

Voltaic cells produce a positive overall charge. what does this indicate? a. the reaction is likely to be endothermic. b. the reaction is spontaneous. c. the reaction is not likely to occur. d. the reaction is not spontaneous.