, ▁bases ▁yield ▁solutions ▁in ▁which ▁the ▁hydro gen ▁ion ▁activity ▁is ▁lower ▁than ▁it ▁is ▁in ▁pure ▁water , ▁i . e ., ▁the ▁water ▁has ▁a ▁p H ▁higher ▁than ▁ 7 . 0 ▁at ▁standard ▁conditions . ▁A ▁sol ub le ▁base ▁is ▁called ▁an ▁alk ali ▁if ▁it ▁contains ▁and ▁releases ▁O H − ▁ ions ▁quant it atively . ▁However , ▁it ▁is ▁important ▁to ▁realize ▁that ▁basic ity ▁is ▁not ▁the ▁same ▁as ▁al kal inity . ▁Metal ▁ox ides , ▁hydro x ides , ▁and ▁especially ▁alk ox ides ▁are ▁basic , ▁and ▁conjug ate ▁bases ▁of ▁weak ▁ac ids ▁are ▁weak ▁bases . ▁ ▁B ases ▁can ▁be ▁thought ▁of ▁as ▁the ▁chemical ▁opposite ▁of ▁ac ids . ▁However , ▁some ▁strong ▁ac ids ▁are ▁able ▁to ▁act ▁as ▁bases . ▁B ases ▁and ▁ac ids ▁are ▁seen ▁as ▁oppos ites ▁because ▁the ▁effect ▁of ▁an ▁acid ▁is ▁to ▁increase ▁the ▁hyd ron ium ▁( H 3 O +) ▁concentration ▁in ▁water , ▁whereas ▁bases ▁reduce ▁this ▁concentration . ▁A ▁reaction ▁between ▁an ▁acid ▁and ▁a ▁base ▁is ▁called ▁neutral ization . ▁In ▁a ▁neutral ization ▁reaction , ▁an ▁a que ous ▁solution ▁of ▁a ▁base ▁react s ▁with ▁an ▁a que ous ▁solution ▁of ▁an ▁acid ▁to ▁produce ▁a ▁solution ▁of ▁water ▁and ▁salt ▁in ▁which ▁the ▁salt ▁separ ates ▁into ▁its ▁component ▁ ions . ▁If ▁the ▁a que ous ▁solution ▁is ▁s atur ated ▁with ▁a ▁given ▁salt ▁sol ute , ▁any