Chemistry 1: Acids and Bases Test

Acid concentration

(Molarity) usually less than 1 of H+ In a glass of water [H+]= 0.0000001 M (molarity) 1x10-7 (neutral)

organic acids

-COOH

pH

-log[H+] Negative logarithm of the concertation of hydrogen ions

pH scale

0-6 acidic 7 neutral 8-14 basic

Bronsted-Lowry theory

1920's- defined acids as hydrogen ion donor and Bases as hydrogen ion receptors Arrhenius theory had some limitations so they expanded the definition of acids and bases An acid is an H+ donor A base is an H+ acceptor H+ is simply a proton which interacts strongly with non bonding e- on the oxygen of a water molecule (protons are not floating, they attach to water molecules and form hydronium) Interaction results in a hydronium ion (H3O+)

10

1x10 10 Log10- 1

0.1

1x10^-1 10^-1 Log10- (-1)

0.01

1x10^-2 10^-2 Log10- (-2)

1

1x10^0 10^0 Log10-0

100

1x10^2 10^2 Log10- 2

1000

1x10^3 10^3 Log 10-3

Covalent

2 nonmetals with prefixs except if there's a 1 for the first non metal

Arrhenius bases

A base is a substance that had OH- (hydroxide) and releases (yields) OH- ions as the only negative ions in an aqueous solution Adding a base to an aqueous solution increases the concentration of OH- ions in the solution thereby decreasing the concertation of H+ and increasing the pH

Titration

A laboratory process in which a volume of solution of known concentration is used to determine the concentration of another solution

Electrolyte

A substance which, when dissolved in water forms a solution capable of conducting an electric current. The ability of a solution to conduct an electric current depends on the concentration of ions. A strong acid or string base dissolves completely in water

Bronsted-Lowry

Acids and bases can be defined in terms of ability to donate protons Acid: proton donor Base: proton acceptor

Acid pH values

Acids have pH values in the range of 0 to 7 and hydronium ion concentration between 0.0 and 0.0000001.

H+

All acids have the _______ ion in common

OH-

All bases have the ______ ion in common

Containing C,H,O or 2 non metals

All other compounds have formulas

Anion+cation

All salts have formulas made of

Arrhenius acids

Always start with H An acid is a substance that had hydrogen and release (yields) H+ ions as the only positive ions I'm solution Adding an acid to an aqueous solution increases the concentration of H+ ions I'm the solution and decrease the pH The H+ ions attach to the H2O (so they don't really float around) forming hydronium ions: H3O+ Can be monprotic, diprotic

Base

Bases end with OH- (hydroxide) Reacts with acids to form a salt and water Are electrolytes

Base pH values

Bases have pH values in the range of 7 to 14 and and the hydronium concentrations between 0.0000001 and 0.00000000000001.

auto ionization of water

Because water is amphoteric, it can actually donate a proton to another water and vice versa This is called auto-ionization No individual molecule remains ionized for long, and at room temperature, only about 1 in 10^9 molecules in ionized at any given moment (1 in 100 billion) Because it's an equilibrium process, we can write an equilibrium expression

Metals that don't react with acids

Coinage metals (gold, silver, copper) Bismuth Mercury

Oxyacids

Contain hydrogen and a polyatomic ion like nitrate or sulfate These polyatomic ions contain O (oxygen)

Names for oxyacids

Depend on whether the polyatomic ion ends in -ate or -ite -ate—> -ic -ite—> -ous Don't have prefix of hydro Example: H3PO4(hydrogen and phosphate)—phosphoric acid HNO3(hydrogen and nitrate)— nitric acid

Strong acids

Disassociate into ions completely

Weak acids

Dissociate only partially into ions (molecules breaks apart into ions

Coinage metals

Don't react with acids Copper, silver, gold

Logarithm

Expresses numbers as a power of 10

Obtaining the pH of an acid or base

Find the -log of the hydronium concentration, therefore pH can also be known as the "power" of the hydronium concentration

Formulas for acids

H has a charge of 1+ Criss cross to add the correct number of H to the anion Example: H+ P3- *criss cross* H3P

Diatomics

H2, N2, O2, F2, Cl2, Br2, I2

Hydronium ion

H3O+

Strong acids

Hydrochloric acid (HCl) Hydrobromic acid (HBr) Hydroiodic acid (HI) Nitric acid (HNO3) Sulfuric acid (H2SO4) Perchloric acid (HClO4) Chloric acid (ClO4)

Conjugate acid-base pairs

In any acid-base equilibrium, both the forward and reverse reactions involve proton transfers HX + H2O—-> X + H3O Forward reaction, HX donates a proton, it is an acid and H2O is the base Reverse reaction, H3O is the acid and X is the base An acid and base that differ only in presence or absence of a proton is called a conjugate acid-base pair

Properties of bases

In aqueous solutions, bases conduct electricity they are also electrolytes Bases cause color changes in acid base indicators Turns pink litmus blue and keeps blue litmus blue Bases react with acids to form a salt and water (H2O) via a double displacement reaction Bitter taste pH levels 8-14 higher the number, the more basic (less acidic) the solution is Common examples: hydroxides of column 1: lithium, potassium, rubidium, sodium) and 3 of column 2: (barium, calcium, strontium) Food/house examples: NaOH (lye in soap) Baking soda (sodium bicarbonate)

Properties of acids

In aqueous solutions, they conduct electricity since they are electrolytes Metals above H2 on an activity series will react with acids to produce a hydrogen gas and a salt (replace H) ex: Mg+HCl—> MgCl+ H2 Acids cause color changes in acid base indicators Acids react with bases to form a salt and water (H2O) (Double displacement reaction, cation always comes first) Blue litmus with acid turn pink Pink litmus with acid stays pink Acids have a sour taste pH levels 0-6 the lower the pH the more acidic Common examples: HCl, HBr, NHO3, H2SO4 Food examples: citric acid (lemons and oranges), acetic acid (vinegar), ascobric acid (vitamin c), carbonic acid (soda)

Weak

In terms ions, does not dissociate completely in a solution

Strong

In terms of ions, fully dissociated at the pH of interest/more cations than anions

Concentrated

In terms of particles, there many particles per volumetric

Dilute

In terms, of amount of particles there are few particles per volume

Ten fold

Increasing or decreasing the pH by 1 changes the [H+] by a factor of 10^1 (10 times, ten fold)

Hundred fold

Increasing or decreasing the pH by 2 changes the [H+] by a factor of 10^2 (100 times, hundred fold)

Thousand fold

Increasing or decreasing the pH by 3 changes the [H+] by a factor of 10^3 (1000, thousand fold)

Salts

Ionic compounds (metal +nonmetal) Are electrolytes

What kind of neutral conduct electricity? In other words, what types of neutral solutions are electrolytes?

Ionic compounds also called salts

Common household acids

Lemon juice, vinegar, calumet

Strong bases

Lithium hydroxide - LiOH Sodium hydroxide - NaOH Potassium hydroxide - KOH Rubidium hydroxide - RbOH Cesium hydroxide - CsOH Calcium hydroxide - Ca(OH)2 Strontium hydroxide - Sr(OH)2 Barium hydroxide - Ba(OH)2

pH scale

Logarithmic PH= -log10 [H+] in solution

pH scale

Measure of the H+ or H3O+ concentration in a solution. pH stands for "potential to attract hydrogen ions" Acids have a low pH (a low potential to attract H+ ions(release/donate H+) Bases gave a high pH (a high potential to attract H+ ions(bases are H+ acceptors) The pH scale is Logarithmic, which means that a change of one pH unit will change the concentration of H+ by a factor of 10)

Concentration

Molarity measures

Comparing the two theories

NH3 (aq) + H2O (l) <——> NH4 (aq) + OH- (aq) NH3 is a base (acceptor) NH4 is the conjugate acid of NH3 (donor) H20 is an acid (donor) OH- is the conjugate base of water (acceptor) Conjugates because of arrows, reactions vary and switch sides According to Arrhenius, NH3 is a base because adding water to it increases the hydroxide ion concentration Bronsted-Lowry classifies it as a base because it accepts a proton from H2O, and the water acts as an acid because it donates a proton Double arrows mean they will break apart but not totally dissociate since the acid is weak

Do all neutral solutions conduct electricity

No

Logarithm in calculator

Number first, the LOG Ex: 856 LOG= 2.9324 roughy 3 almost 10^3

7

On Ph scale is neutral

pH scale

On the pH scale, each decrease of one unit of pH represents a tenfold increase in hydronium ion concentration

Alternate base theories

One theory states that an acid is an H+ donor and a base is an H+ acceptor (Bronsted-Lowry)

COOH

Organic acids have the general formula

Common household bases

Parsons ammonia, oven cleaner, Draino, baking soda

What is the universal Indicator color for a substance that is very acidic? (pH=2)

Red

Propeties of salts

Salts are any ionic compound (cation+anion) Like bases, salts are also electrolytes Salts are formed as a product of neutralization reactions (acid +base—-> salt+ water) Neural—> most have a pH of about 7 Examples: NaCl, Ca(NO3)2, KCl, NaI, Al2O3, NH4, NO3

Acid formulas

Start with H (hydrogen) Hydrogen is a nonmetal to acids are covalent Are electrolytes

Amphoteric substances

Substances that can act as an acid or base Best example is H2O (water) With ammonia it's an acid With HCl it's a base

Arrhenius theory

Svante Arrhenius- mid to late 1800's, Nobel prize:1903 Based on his ideas on the fact that aqueous solutions of acids and based are electrolytes (even tho they are covalent, they act like ionic compounds) Said that the properties of acids and bases are because of their H+ and OH- ions (OH- is hydroxide)

Acidity and Alkalinity

The acidity and alkalinity of a solution can be measured by its pH value the relative level of acidity or alkalinity of a solution can be shown by using indicators

Names for binary acids

Use prefix hydro Name root of nonmetal Use suffix -ic State or write the word "acid" Example: H2S— hydrosulfuric acid HF— hydrofluoric acid

acid-base reaction (neutralization)

When an acid and base mix together, neutralize one another's properties, and form a salt. Ex: Mg(OH) + H2SO4-> MgSo4+ H2O

What is the universal indicator color for a substance that is a string base? (pH 10 or above)

Yellow

What is the universal indicator color for a substance that is neutral? (pH 7)

Yellow

Do all acid solutions conduct electricity

Yes

Do all basic (alkaline) solutions conduct electricity

Yes

What can you learn about a solution using a conductivity test

You can tell whether the solution contains ions, also called electrolytes, but you cannot tell whether those ions are acidic hydrogen ions, basic hydroxide ions, or neutral metal and nonmetal ions

What can you tell about a solution by using a phenolphthalein

You can tell whether the solution is a base with a pH of about 10 or higher because the solution will turn pink

What can you tell about the pH of a solution by adding bromocresol green?

You will see yellow if the pH is acidic and below 3

Concentration

[H+]

Triprotic acid

an acid able to donate three protons per molecule Examples: H3P, H3PO4, H3PO3

monoprotic acid

an acid that can donate only one proton (hydrogen ion) per molecule Can by binary or oxyacids Examples: HCl, HF, HBr, HI, HNO3

diprotic acid

an acid that can donate two protons per molecule Can be binary or oxyacid Examples: H2S, H2Se, H2Co3, H2Cl, H2SO4

Binary acids

contain hydrogen and one other element (nonmetal) Binary=2 Always have prefix Hydro and end in -ic acid (H+ nonmetal anion)

Ionic

metal + nonmetal or a polyatomic