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IONIC REACTIONS 11/02/09. DISSOCIATION OF A SOLLUBLE SALT. 1) Soluble salts (table F) dissociate (break up) by separating into a positive and negative ions in the solvent water. 2) The ions become mobile as they dissolve and therefore are able to conduct an electrical current.
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IONIC REACTIONS 11/02/09 DISSOCIATION OF A SOLLUBLE SALT. 1) Soluble salts (table F) dissociate (break up) by separating into a positive and negative ions in the solvent water. 2) The ions become mobile as they dissolve and therefore are able to conduct an electrical current. SKILL – WRITIND DISSOCIATIONS. STEP ONE: WRITE THE FORMULA STEP TWO: USING TABLE E AND/OR PERIODIC TABLE , OBTAIN THE CHARGES OF THE IONS OR REVERSE THE CRISS CROSS METHOD. STEP THREE: WRITE THE DISSOCIATION. Example one; Write the dissociation of KF. STEP ONE: WRITE THE FORMULA KF. STEP TWO: USING TABLE E AND/OR TABLE S, OBTAIN THE CHARGES OF THE IONS OR REVERSE THE CRISS CROSS METHOD. a) K+ andF- K is +1 as with all group one elements F is -1 as with all halides in binary salts.
Example one; Write the dissociation of KF. STEP ONE: WRITE THE FORMULA KF. STEP TWO: USING TABLE E AND/OR TABLE S, OBTAIN THE CHARGES OF THE IONS OR REVERSE THE CRISS CROSS METHOD. a) K+ andF- b) WRITE THE DISSOCIATION REACTION, (WITH PHASES) KF(s) K+(aq)+ F-(aq) OR YOU CAN “CROSS CRISS” ( THE SUBSCRIPT OF THE METAL BECOMES THE - CHARGE OF THE NONMETAL AND THE + CHARGE OF THE METAL. K F K+1 F-1 KF(s) K+(aq) + F-(aq)
Example one; Write the dissociation of Ca(NO3)2. STEP ONE: WRITE THE FORMULA Ca(NO3)2. STEP TWO: USING TABLE E AND/OR TABLE S, OBTAIN THE CHARGES OF THE IONS OR REVERSE THE CRISS CROSS METHOD. a) Ca+2 andNO3- b) WRITE THE DISSOCIATION REACTION, (WITH PHASES) Ca(NO3)2(s) Ca+2(aq)+ 2NO3-(aq) Table E gives the charge of EACH nitrate as -1 Ca is +2 as with all group two elements OR YOU CAN “CROSS CRISS” ( THE SUBSCRIPT OF THE METAL BECOMES THE - CHARGE OF THE NONMETAL AND THE SUNSCRIPT OF THE NONMETAL POLY-ION BECOMES THE + CHARGE OF THE METAL. Ca(NO3)2 Ca(NO3)2(s) Ca+2(aq) + 2NO3-(aq)
Example one; Write the dissociation of Fe(II)SO4. STEP ONE: WRITE THE FORMULA Fe(II)SO4. STEP TWO: USING TABLE E AND/OR TABLE S, OBTAIN THE CHARGES OF THE IONS OR REVERSE THE CRISS CROSS METHOD. a) Fe+2 andSO4-2 b) WRITE THE DISSOCIATION REACTION, (WITH PHASES) Fe(II)SO4(s) Fe+2(aq)+ SO4-2(aq) Table E gives the charge of EACH sulfate as -2 Fe is +2 as with as indicated by the Roman numeral (II) DO NOT USE THE CROSS-CRISS METHOD WITH ROMAN NUMERALS
TRY THESE NOW, WRITE DISSOCIATION K2Cr2O7 2 K+ + Cr2O72- Pb(NO3)2 Pb+2 + 2 NO3- Zn(III)(NO3)3Zn+3 + 3 NO3-