Unit 11: Acids and Bases Tyna L. Meeks

Unit 11: Acids and Bases Acids and Bases can also be identified by certain chemical properties AcidBase turns red in litmusturns blue in litmus conduct electricityconduct electricity sour tastebitter taste tingle/painslippery reacts w/ metal to produce H 2 gas produce H 2 gas

Unit 11: Acids and Bases Acids and Bases can also be identified by certain chemical properties AcidBase causes other causes other indicators to turn indicators to turn colors (Table M) colors (Table M) reacts with base to reacts with acid to form salt water form salt water

Unit 11: Acids and Bases Acids and Bases can also be identified by certain chemical properties Arrhenius Definition AcidBase One or more H + Many include OH - that can be released.in their structure, or “acidic hydrogens”they react with H 2 O to produce OH - ions.

Unit 11: Acids and Bases Acids and Bases can also be identified by certain chemical properties Bronsted-Lowry Definition AcidBase DONATE H + ACCEPT H + “acidic hydrogens”

Unit 11: Acids and Bases Certain substances display neither acidic or basic properties and are considered to be neutral. Others may display BOTH and are called amphoteric!! Acidic and basic solutions have effects on living organisms!

Unit 11: Acids and Bases Structure Determines Function Naming Acids and Bases: 3binary acids: composed of hydrogen and one other atom, 3 to name it start with hydro-, name the second atom, and change the ending to -ic

Unit 11: Acids and Bases Structure Determines Function Naming Acids and Bases: 3ternary acids: composed of hydrogen and two other atoms, commonly called oxy acids because the third atom is normally oxygen. 3 To name it find the polyatomic ion it comes from and change its ending accordingly 3if the polyatomic ion ends in -ite, change ending to -ous if the polyatomic ion ends in -ate, change ending to -ic

Unit 11: Acids and Bases pH and Acidity 3based on the concentration of the H + ion or OH - ion 3in an acid the H + ion concentration is higher 3 the concentration are very small, in the negative exponents 3 these exponents are turned into whole numbers on the scale 3 every ten times higher it moves ‘down’ the pH scale

Unit 11: Acids and Bases pH and Acidity

Unit 11: Acids and Bases pH, indicators, and Acidity Reading: Bromothymol blue turned BLUE Phenlphthalein is COLORLESS Phenlphthalein is COLORLESS ► Based on the indicator results, what is possible pH of rainwater? ► What substance would you add to neutralize this solution of rainwater, an acid or base?

Unit 11: Acids and Bases pH and Acidity Adding substance X to a liter of neutral solution made the solution 100 times more acidic. ► What ion increased in concentration? ► What is the pH of the new acidic solution?

Unit 11: Acids and Bases A truck carrying concentrated sodium hydroxide overturns and spills its contents. The base drains into a nearby pond. The pH of the pond water was 8.0 before the spill. After the spill, the pond water’s pH was altered by a factor of 2. ► Name an ion in the pond that has increased in concentration due to the spill. ► How much did the concentration of the base increase? ► What color would bromcresol green be at this new pH?

Unit 11: Acids and Bases Reactions Involving Acids and Bases Reactions of Acids with Metals Zn(s) + 2HCl(aq)  ZnCl 2 (aq) + H 2 (g) Zn(s) + 2HCl(aq)  ZnCl 2 (aq) + H 2 (g) Single Replacement Reaction (Table J) Single Replacement Reaction (Table J) Metal must be higher than the acid ion (H + ) Metal must be higher than the acid ion (H + ) Produces hydrogen gas Produces hydrogen gas

Unit 11: Acids and Bases

Reactions Involving Acids and Bases Neutralization H 2 SO 4 + Ca(OH) 2  2HOH + CaSO 4 H 2 SO 4 + Ca(OH) 2  2HOH + CaSO 4 2H + + 2OH -  2HOH 2H + + 2OH -  2HOH 2H 3 O + + 2OH -  4HOH 2H 3 O + + 2OH -  4HOH

Unit 11: Acids and Bases

Reactions Involving Acids and Bases Hydrolysis of a Salt Salt dissolves to produce an acid and a base Salt dissolves to produce an acid and a base Determine the strength of each to determine the overall pH of the solution Determine the strength of each to determine the overall pH of the solution 2HOH  2H + + 2OH - 2HOH  2H + + 2OH - 2HOH + CaSO 4  H 2 SO 4 + Ca(OH) 2 2HOH + CaSO 4  H 2 SO 4 + Ca(OH) 2

Unit 11: Acids and Bases Titrations 3the process of adding measured volumes of acid or base of known concentration to an acid or base of unknown concentration until neutralization occurs 3determined by an indicator color change 3 usually phenolphthalein is used 3Moles of acid = Moles of base 3M A V A = M B V B