1 Nonelectrolytes electrolytes or nonelectrolytes? If electrolytes - PDF document

What types of compounds electrolytes dissociate in water to give ions? Acids •Covalent compound having any anion with a H + • Electrolytes = acids, bases and soluble salts •begin with H Do not dissociate into ions: •Generate H + ions in aq. sol’n • Nonelectrolytes = covalent and organic • Ex- HCl, HBr, H 2 SO 4 , HNO 3 , H 2 CO 3 compounds, precipitates electrolytes Bases •Strong = any soluble metal cation + OH - Ex- NaOH, KOH •Weak = NH 3 Generate OH - ions in aq. sol’n electrolytes Soluble salts = ionic compounds Any cation (other than H + ) + any anion (other than OH - ) ex: NaCl Mg(ClO 3 ) 2 (NH 4 ) 3 PO 4 Soluble: produces ions = electrolyte Insoluble: nonelectrolyte 1

Nonelectrolytes electrolytes or nonelectrolytes? If electrolytes write equations showing them dissociate: Covalent compounds HBr � H + + Br - HBr � Comp’d of nonmetals together (except for acids) C 6 H 6 Ex- BrF 5 XeF 4 SF 6 Sr(OH) 2 � Sr +2 + 2OH - Sr(OH) Sr(OH) 2 � Organic compounds C 6 H C 6 H 12 O 6 12 Comp’d containing C, H, and possibly Na 2 S � Na + + S 2- Na 2 S Na 2 S other elements Ex- CH 4 C 12 H 24 O 12 C 3 H 7 OH + + NO 3 - NH 4 NO 3 � NH 4 NH 4 NO 3 sugar alcohol + + OH - NH 3 + H 2 O � NH 4 NH 3 NH 3 + H 2 O � � H + + CH 3 COO - CH 3 COOH � Why does a chemical reaction occur? Precipitation Reactions There has to be a driving force 1. Formation of: 1) precipitate 2) water NaCl (aq) + AgNO 3(aq) � NaNO 3 + AgCl NaCl (aq) + AgNO 3(aq) � NaCl (aq) + AgNO 3(aq) � NaNO 3 3) gas What products are formed? Molecular equation show molecules NaCl (aq) + AgNO 3(aq) � NaNO 3 (aq) + AgCl (s) (s) = solid or precipitate ionic equations show ions for those that dissociate A) Complete ionic + +Cl + +Cl + +Cl + +Cl - + Ag - + Ag - + Ag + +NO 3 + +NO 3 + +NO 3 + +NO 3 + +NO 3 - � Na - � Na - + AgCl (s) - - - Na Na Na Na B) net ionic - + Ag + � AgCl (s) Cl 2

Predict products and then write molecular and Predict products and then write molecular and net ionic equations. net ionic equations. BaCl 2(aq) + K 2 CO 3(aq) � BaCO 3 + 2KCl 2. Molecular equation BaCl 2(aq) + K 2 CO 3(aq) � BaCO 3(s) + 2KCl (aq) + +CO 3 + +2Cl -2 � BaCO 3(s) -2 � +2 +2Cl - - Ba l +2K s) + 2K Net ionic equation +2 +CO 3 -2 � BaCO Ba 3(s Predict products and then write molecular and Predict products and then write molecular and net ionic equations. net ionic equations. 3. Molecular equation 3. Molecular equation NaOH (aq) + KNO 3(aq) � NaNO 3 + KOH NaOH (aq) + KNO 3(aq) � NaNO 3 + KOH No precipitate formed + +OH + +OH + +OH + +OH - +K - +K - +K + + NO 3 + + NO 3 + + NO 3 + + NO 3 + + NO 3 + +OH - � Na - � - � Na � + K - - Na Na Na Na � No reaction Nothing new formed Lab 11: Reactions between ions in AgNO 3 CuSO 4 Na 2 S KI aqueous sol’n Directions: AgNO 3 • Ag(SO 4 ) 2 solid Do not contaminate solutions. Let each • • Cu(NO 3 ) 2 (aq) drop fall off end of bottle onto plate. • observations Make precipitates with several possible CuSO 4 • combinations of 12 solutions In grid write: • Na 2 S • K 2 S (aq) a. Products of reaction • NaI (aq) • No rxn b. Observations (color and appearance KI of precipitate) 3

Potassium hydroxide is mixed with sulfuric acid: Neutralization reaction = acid and base yield water and salt Molecular equation KOH (aq) KOH (aq) + H 2 SO 4(aq) � K 2 SO 4(aq) + HOH (l) K 2 SO 4(aq) 2 2 1) Calcium hydroxide is mixed with hydrochloric acid. Ca(OH) 2(aq) + 2HCl (aq) � CaCl 2(aq) (aq) + 2HOH (l) acid salt base Complete ionic equation 2K +1 + 2OH - - + 2H + + SO 4 -2 � 2K +1 + SO 4 -2 + 2HOH Net ionic equation OH - (aq) + H + (aq) � HOH (l) Calcium hydroxide is mixed with nitric acid: Molecular equation Ca(OH) 2 + HNO 3 � Ca(NO 3 ) 2(aq) + HOH Ca(OH) 2 Ca(OH) 2 + HNO 3 � Ca(NO 3 ) 2(aq) Ca(OH) 2 + HNO 3 � 2 2 Complete ionic equation Ca +2 + 2OH - + 2H + +2NO 3 Ca +2 + 2OH - + 2H + +2NO 3 Ca +2 + 2OH - + 2H + Ca +2 + Ca +2 + 2OH - -1 � -1 � Ca +2 + 2NO 3 -1 + 2HOH Net ionic equation OH - (aq) + H + (aq) � HOH (l) 4