▁form ▁free ▁ ions . ▁ ▁A ▁weak ▁electro ly te ▁is ▁a ▁subst ance ▁whose ▁sol ute ▁exists ▁in ▁solution ▁mostly ▁in ▁the ▁form ▁of ▁mole cules ▁( which ▁are ▁said ▁to ▁be ▁" und is soci ated "), ▁with ▁only ▁a ▁small ▁fraction ▁in ▁the ▁form ▁of ▁ ions . ▁Sim ply ▁because ▁a ▁subst ance ▁does ▁not ▁readily ▁dissol ve ▁does ▁not ▁make ▁it ▁a ▁weak ▁electro ly te . ▁Ac etic ▁acid ▁( CH 3 CO OH ) ▁and ▁am mon ium ▁( N H 4 +) ▁are ▁good ▁examples . ▁Ac etic ▁acid ▁is ▁extremely ▁sol ub le ▁in ▁water , ▁but ▁most ▁of ▁the ▁comp ound ▁dissol ves ▁into ▁mole cules , ▁rendering ▁it ▁a ▁weak ▁electro ly te . ▁We ak ▁bases ▁and ▁weak ▁ac ids ▁are ▁generally ▁weak ▁electro ly tes . ▁In ▁an ▁a que ous ▁solution ▁there ▁will ▁be ▁some ▁CH 3 CO OH ▁and ▁some ▁CH 3 CO O − ▁and ▁H + . ▁ ▁A ▁strong ▁electro ly te ▁is ▁a ▁sol ute ▁that ▁exists ▁in ▁solution ▁completely ▁or ▁nearly ▁completely ▁as ▁ ions . ▁Again , ▁the ▁strength ▁of ▁an ▁electro ly te ▁is ▁defined ▁as ▁the ▁percentage ▁of ▁sol ute ▁that ▁is ▁ ions , ▁rather ▁than ▁mole cules . ▁The ▁higher ▁the ▁percentage , ▁the ▁stronger ▁the ▁electro ly te . ▁Thus , ▁even ▁if ▁a ▁subst ance ▁is ▁not ▁very ▁sol ub le , ▁but ▁does ▁dis soci ate ▁completely ▁into ▁ ions , ▁the ▁subst ance