Unit 11: Acids and Unit 11: Acids and BasesBases

Tyna L. MeeksTyna L. Meeks

Unit 11: Acids and BasesUnit 11: Acids and BasesAcids and Bases can also be identified by certain Acids and Bases can also be identified by certain

chemical propertieschemical propertiesAcidAcidBaseBase

turns red in litmusturns red in litmus turns blue in litmusturns blue in litmusconduct electricityconduct electricity conduct electricityconduct electricitysour tastesour taste bitter tastebitter tastetingle/paintingle/painslipperyslipperyreacts w/ metal toreacts w/ metal to produce Hproduce H22 gas gas

Unit 11: Acids and BasesUnit 11: Acids and BasesAcids and Bases can also be identified by Acids and Bases can also be identified by

certain chemical propertiescertain chemical propertiesAcidAcidBaseBase

causes other causes other causes other causes other indicators to turn indicators to turn indicators to turn indicators to turncolors (Table M)colors (Table M) colors (Table M) colors (Table M)

reacts with base to reacts with base to reacts with acid toreacts with acid toform salt waterform salt water form salt water form salt water

Unit 11: Acids and BasesUnit 11: Acids and Bases

Acids and Bases can also be identified by Acids and Bases can also be identified by certain chemical propertiescertain chemical propertiesArrhenius DefinitionArrhenius DefinitionAcidAcidBaseBase

One or more One or more HH++ Many include Many include OHOH--

that can be released.that can be released. in their structure, orin their structure, or““acidic hydrogens”acidic hydrogens” they react with Hthey react with H22O O to to

produce OHproduce OH-- ions. ions.

Unit 11: Acids and BasesUnit 11: Acids and Bases

Acids and Bases can also be identified by Acids and Bases can also be identified by certain chemical propertiescertain chemical propertiesBronsted-Lowry DefinitionBronsted-Lowry DefinitionAcidAcidBaseBase

DONATE DONATE HH++ ACCEPT ACCEPT HH++

““acidic hydrogens”acidic hydrogens”

Unit 11: Acids and BasesUnit 11: Acids and BasesCertain substances display neither acidic Certain substances display neither acidic

or basic properties and are considered or basic properties and are considered to be neutral.to be neutral.

Others may display BOTH and are called Others may display BOTH and are called amphoteric!!amphoteric!!

Acidic and basic solutions have effects on Acidic and basic solutions have effects on living organisms!living organisms!

Unit 11: Acids and BasesUnit 11: Acids and BasesStructure Determines FunctionStructure Determines FunctionNaming Acids and Bases:Naming Acids and Bases:

binary acids: composed of binary acids: composed of hydrogenhydrogen and and oneone other atom, other atom,

to name it start with hydro-, name the second to name it start with hydro-, name the second atom, and change the ending to -icatom, and change the ending to -ic

Unit 11: Acids and BasesUnit 11: Acids and BasesStructure Determines FunctionStructure Determines FunctionNaming Acids and Bases:Naming Acids and Bases:

ternary acids: composed of ternary acids: composed of hydrogenhydrogen and and twotwo other atoms, commonly other atoms, commonly called called

oxy acids because the oxy acids because the third atom is third atom is normally normally oxygenoxygen. . To name it find the polyatomic ion it comes from To name it find the polyatomic ion it comes from

and change its ending accordinglyand change its ending accordingly if the polyatomic ion ends in -ite, change ending to -ousif the polyatomic ion ends in -ite, change ending to -ous

if the polyatomic ion ends in -ate, if the polyatomic ion ends in -ate, change ending to -icchange ending to -ic

Unit 11: Acids and BasesUnit 11: Acids and BasespH and AciditypH and Acidity

based on the concentration of the Hbased on the concentration of the H+ + ion or ion or OHOH-- ion ion

in an acid the Hin an acid the H++ ion concentration is higher ion concentration is higher the concentration are very small, in the the concentration are very small, in the

negative exponentsnegative exponents these exponents are turned into whole numbers these exponents are turned into whole numbers

on the scaleon the scale every ten times higher it moves ‘down’ the pH every ten times higher it moves ‘down’ the pH

scalescale

Unit 11: Acids and BasesUnit 11: Acids and BasespH and AciditypH and Acidity

Unit 11: Acids and BasesUnit 11: Acids and BasespH, indicators, and AciditypH, indicators, and AcidityReading: Bromothymol blue turned BLUEReading: Bromothymol blue turned BLUE Phenlphthalein is COLORLESSPhenlphthalein is COLORLESS► Based on the indicator results, what is Based on the indicator results, what is

possible pH of rainwater?possible pH of rainwater?► What substance would you add to What substance would you add to

neutralize this solution of rainwater, neutralize this solution of rainwater, an acid or base?an acid or base?

Unit 11: Acids and BasesUnit 11: Acids and BasespH and AciditypH and AcidityAdding substance X to a liter of neutral Adding substance X to a liter of neutral

solution made the solution 100 times solution made the solution 100 times more acidic.more acidic.

► What ion increased in concentration?What ion increased in concentration?► What is the pH of the new acidic What is the pH of the new acidic

solution?solution?

Unit 11: Acids and BasesUnit 11: Acids and BasesA truck carrying concentrated sodium hydroxide A truck carrying concentrated sodium hydroxide

overturns and spills its contents. The base overturns and spills its contents. The base drains into a nearby pond. The pH of the drains into a nearby pond. The pH of the pond water was 8.0 before the spill. After pond water was 8.0 before the spill. After the spill, the pond water’s pH was altered by the spill, the pond water’s pH was altered by a factor of 2.a factor of 2.

► Name an ion in the pond that has increased Name an ion in the pond that has increased in concentration due to the spill.in concentration due to the spill.

► How much did the concentration of the base How much did the concentration of the base increase?increase?

► What color would bromcresol green be at What color would bromcresol green be at this new pH?this new pH?

Unit 11: Acids and BasesUnit 11: Acids and BasesReactions Involving Acids and BasesReactions Involving Acids and Bases

Reactions of Acids with MetalsReactions of Acids with MetalsZn(s) + 2HCl(aq) Zn(s) + 2HCl(aq) ZnCl ZnCl22(aq) + H(aq) + H22(g)(g)Single Replacement Reaction (Table J)Single Replacement Reaction (Table J)

Metal must be higher than the acid ion (HMetal must be higher than the acid ion (H++))Produces hydrogen gasProduces hydrogen gas

Unit 11: Acids and BasesUnit 11: Acids and Bases

Unit 11: Acids and BasesUnit 11: Acids and BasesReactions Involving Acids and BasesReactions Involving Acids and Bases

NeutralizationNeutralization HH22SOSO44 + Ca(OH) + Ca(OH)22 2HOH + CaSO 2HOH + CaSO44

2H2H++ + 2OH + 2OH-- 2HOH 2HOH 2H2H33OO+ + + 2OH+ 2OH-- 4HOH 4HOH

Unit 11: Acids and BasesUnit 11: Acids and Bases

Unit 11: Acids and BasesUnit 11: Acids and Bases

Unit 11: Acids and BasesUnit 11: Acids and BasesReactions Involving Acids and BasesReactions Involving Acids and Bases

Hydrolysis of a SaltHydrolysis of a Salt Salt dissolves to produce an acid and a baseSalt dissolves to produce an acid and a base

Determine the strength of each to determine the Determine the strength of each to determine the overall pH of the solutionoverall pH of the solution

2HOH 2HOH 2H 2H++ + 2OH + 2OH-- 2HOH + CaSO2HOH + CaSO44 H H22SOSO44 + Ca(OH) + Ca(OH)22

Unit 11: Acids and BasesUnit 11: Acids and BasesTitrationsTitrations

the process of adding measured volumes the process of adding measured volumes of acid or base of known concentration to of acid or base of known concentration to an acid or base of unknown concentration an acid or base of unknown concentration until neutralization occursuntil neutralization occurs

determined by an indicator color changedetermined by an indicator color change usually phenolphthalein is usedusually phenolphthalein is used

Moles of acid = Moles of baseMoles of acid = Moles of baseMMAAVVAA = M = MBBVVBB