1 Nonelectrolytes electrolytes or nonelectrolytes? If electrolytes - - PDF document

SLIDE 1

1

What types of compounds dissociate in water to give ions?

• Electrolytes = acids, bases and soluble salts
• Nonelectrolytes = covalent and organic

compounds, precipitates

Do not dissociate into ions:

electrolytes Acids

• Covalent compound having any anion

with a H+

• begin with H
• Generate H+ ions in aq. sol’n
• Ex- HCl, HBr, H2SO4, HNO3, H2CO3

electrolytes Bases

• Strong = any soluble metal cation + OH-

Ex- NaOH, KOH

• Weak = NH3

Generate OH- ions in aq. sol’n electrolytes Soluble salts = ionic compounds Soluble: nonelectrolyte produces ions = electrolyte Any cation (other than H+) + any anion (other than OH-) Insoluble: ex: NaCl Mg(ClO3)2 (NH4)3PO4

SLIDE 2

2

Nonelectrolytes Covalent compounds Comp’d of nonmetals together (except for acids) Ex- BrF5 XeF4 SF6 Comp’d containing C, H, and possibly

• ther elements

Ex- CH4 C12H24O12

C3H7OH

Organic compounds

sugar alcohol electrolytes or nonelectrolytes? If electrolytes write equations showing them dissociate:

HBr C6H6 Sr(OH) C6H

12

Na2S Sr(OH)2 C6H

12O6

Na2S NH4NO3 NH3 CH3COOH HBr H+ + Br- Sr(OH)2 Sr+2 + 2OH- Na2S Na+ + S2- NH4NO3 NH4

+ + NO3

• NH3 + H2O

NH3 + H2O NH4

+ + OH-

H+ + CH3COO-

There has to be a driving force Formation of: 1) precipitate 2) water 3) gas Why does a chemical reaction occur? Precipitation Reactions

NaCl(aq) + AgNO3(aq) NaNO 3

What products are formed?

NaCl(aq) + AgNO3(aq) NaCl(aq) + AgNO3(aq) NaNO 3 + AgCl

1.

NaCl(aq) + AgNO

3(aq) NaNO 3 (aq)+ AgCl(s)

(s) = solid or precipitate Molecular equation show molecules ionic equations show ions for those that dissociate

Na

+ +Cl

• A) Complete ionic

B) net ionic

Cl

• + Ag

+ AgCl(s)

Na

+ +Cl

• + Ag

+ +NO3

• Na

+ +Cl

• + Ag

+ +NO3

• Na

+ +NO3

• Na

+ +Cl

• + Ag

+ +NO3

• Na

+ +NO3

• + AgCl(s)

SLIDE 3

3

BaCl2(aq) + K2CO3(aq)

Predict products and then write molecular and net ionic equations.

BaCO

3 + 2KCl

2. Predict products and then write molecular and net ionic equations.

BaCl2(aq) + K2CO3(aq) BaCO

3(s)+ 2KCl(aq)

Molecular equation Net ionic equation

Ba

+2+2Cl

• Ba

+2+CO3

• 2 BaCO

3(s

l +2K

+ +CO3

• 2
• 2 BaCO3(s)

s)+ 2K + +2Cl

• Predict products and then write molecular and

net ionic equations.

NaOH(aq) + KNO3(aq) NaNO

3+ KOH

• 3. Molecular equation

Predict products and then write molecular and net ionic equations. Molecular equation No precipitate formed

Na

+ +OH

• Na

+ +OH

• +K

+ + NO3

Na

+ +OH

• +K

+ + NO3

• Na

+ + NO3

• Na

+ +OH

• +K

+ + NO3

• Na

+ + NO3 + K + +OH

• No reaction

Nothing new formed 3.

NaOH(aq) + KNO3(aq) NaNO

3+ KOH

Lab 11: Reactions between ions in aqueous sol’n

Directions:

• Do not contaminate solutions. Let each

drop fall off end of bottle onto plate.

• Make precipitates with several possible

combinations of 12 solutions

• In grid write:
• a. Products of reaction
• b. Observations (color and appearance
• f precipitate)
• Ag(SO4)2 solid
• Cu(NO3)2(aq)
• observations

KI Na2S CuSO4 AgNO3 KI Na2S CuSO4 AgNO3

• K2S (aq)
• NaI (aq)
• No rxn

SLIDE 4

4

= acid and base yield water and salt Neutralization reaction base acid salt

Ca(OH)2(aq)

1) Calcium hydroxide is mixed with hydrochloric acid.

+ 2HCl(aq) CaCl2(aq)

(aq) + 2HOH(l)

KOH (aq)

OH-

(aq)+ H+ (aq) HOH (l)

Molecular equation Complete ionic equation Net ionic equation

2K+1 + 2OH-

• + 2H+ + SO4
• 2 2K+1 + SO4
• 2

+ 2HOH

K 2SO4(aq)

Potassium hydroxide is mixed with sulfuric acid:

KOH (aq) + H2SO4(aq)K 2SO4(aq)+ HOH (l)

2 2

Ca(OH)2

Molecular equation Complete ionic equation Net ionic equation

OH -

(aq) + H+ (aq) HOH (l)

Calcium hydroxide is mixed with nitric acid:

Ca(OH)2 + HNO 3 Ca(OH)2 + HNO 3 Ca(NO 3)2(aq) Ca(OH)2 + HNO 3 Ca(NO 3)2(aq) + HOH

Ca+2+

2 2

Ca+2+ 2OH- Ca+2+ 2OH- + 2H+ Ca+2+ 2OH- + 2H+ +2NO 3

• 1

Ca+2+ 2OH- + 2H+ +2NO 3

• 1 Ca+2

+ 2NO3

• 1

+ 2HOH