Chapter 14/15 Acids and Bases

What is the [H3O+] of pure water at 25c is this true at all temps

1 x 10^-7

Identify and describe the characteristic properties of 5 common acids used in industry.

1)Sulfuric acid- removes oxidation in iron during steel manufacturing 2)Nitric acid- used in the production of fertilizers 3)Acetic acid- used as a solvent and in vinegar 4)Hydrochloric acid- used in the production of pvc plastic & in gelatin 5)Hydrofloric acid- used in making teflon and Prozac

How to name a binary acid

1. Begins with the prefix hydro- 2. The root of the name of the second element follows this prefix 3. Ends with the suffix -ic

Conjugate base

A base that forms when an acid loses a proton

Arrhenius Acid

A chemical compound that increases the concentration of hydrogen ions H+ in aqueous solution

Brønsted-Lowry Base

A molecule or ion that is a proton acceptor (NaOH)

Brønsted-Lowry Acid

A molecule or ion that is a proton donor (HCl)

Explain how changes in pH affect the color of an indicator

A pH indicator is a substance that changes color around a particular pH value. It is a weak acid or weak base and the color change occurs around 1 pH unit either side of its acid dissociation constant value.

Arrhenius Base

A substance that increases the concentration of hydroxide ions OH- in aqueous solution

Define and write an equation for each: a conjugate base and a conjugate acid.

Acid + Base → Conjugate Base + Conjugate Acid A conjugate pair refers to acids and bases with common features. These common features are the equal loss/gain of protons between the pairs. Conjugate acids and conjugate bases are characterized as the acids and bases that lose or gain protons. In an acid-base reaction, and acid plus a base reacts to form a conjugate base plus a conjugate acid. The conjugate acid of a base is formed when the base gains a proton.

What distinguishes strong acids from weak acids

Acid are distinguished as weak or strong acids depending on the extent to which the H+ ions disassociate in water.

Compare the general properties of acids with the general properties of bases

Acids: React with most metals to form hydrogen gas, Taste sour, Frequently feel "sticky", Usually gases or liquids bases: Feel "slippery", Taste bitter , React with oils and greases, Frequently solids

Binary Acid

An acid that contains only 2 different elements: hydrogen and 1 of the more electronegative elements - inorganic acids (HF, HCl, HBr, HI)

Oxyacid

An acid that is a compound of hydrogen, oxygen, and a third element, usually a nonmetal (Nitric acid- HNO3)

Weak Acid

An acid that releases few hydrogen ions in aqueous solution. Weak electrolyte (HCN)

Salt

An ionic compound composed of a cation from a base and an anion from an acid

Lewis acid

And Adam ion or molecule that excepts and electron pair to form a covalent bond

Lewis base

And Adam ion or molecule the donuts and electron pair to form a covalent bond

Triprotic acid

And acid able to donate three protons per molecule

Polyprotic acid

And acid that can donate more than one proton for molecule H2SO4

Monoprotic acid

And acid that can donate only one proton (hydrogen ion) for molecule HClO4

Conjugate acid

And acid that forms when a base gains a proton

Amphoteric

Any species that can react as either an acid or a base

Give examples of strong and weak acids

Strong: HCl Weak: Ch3COOH

What can be observed about the rate of change of the pH of a solution near the end point of a titration

first slow and then it speeds up when reaching the point titration

What does it mean when the formula of a particular ion or molecule is enclosed in brackets

indicates the molecule's concentration

Why is pure water a very weak electric conductor

it has very few ions

Explain and illustrate what is meant by the common logarithm of a number

the common logarithm of a number is the power of 10 which equals that number. log 10 = 1, because 10^1 = 10 log 100 = 2, because 10^2 = 100 log 1000 = 3, because 10^3 = 1000

What is meant by the end point of a titration

the substance has transformed into a either a base or acid from whichever it originally was

Without using an indicator how can you determine the equivalence point of a titration experiment or the pH of a solution

use a pH meter to check the pH level as it changes from acidic to basic

On What basis is an indicator selected for a particular titration experiment

you pick the indicator by the strength of the acids/bases

What determines the strength of an Arrhenius acid and base

Bases are distinguished as weak or strong bases depending on the extent to which the OH- ions disassociate in water. strong: NaOH weak: NH3

Distinguish between binary acids and Oxyacids in terms of their component elements and the systems used in naming them

Binary acids are composed of only two elements: H and some non-metal. They are named with the prefix "hydro", then the root of the nonmetal name, then the suffix "ic", then the word "acid". Oxyacids have three elements: H, O, and some nonmetal. The higher is named by the root of the nonmetal's name, followed by the suffix "ic" and the lower has the suffix "ous" .

Acid-base indicators

Compounds who's colors are sensitive to pH (phenolphthalein)

pH meter

Determines the pH of a solution by measuring the voltage between the two electrodes are placed in the solution.

What trend is there in the favored direction of proton transfer reactions

Proton transfer reactions favor the production of the weaker acid and the weaker base.

Brønsted-Lowry Acid-Base reaction

Protons are transferred from one reactant (the acid) to another (the base) HCl + NH3

Why is pure HCl dissolved in a nonpolar solvent exhibit none of the properties of an Arrhenius acid

HCI exhibits Arrhenius properties because it is a compound which releases hydrogen ions (H+) when placed in a solution

What is the relationship between the strength of an acid and the strength of its conjugate base

If the acid is strong then the conjugate base is weak and if the acid is weak then conjugate base strong.

What is the relationship between the strength of a base and the strength of its conjugate acid

If the base is strong then the conjugate acid is weak and if the base is weak then conjugate acid strong.

Which of the three acid definitions is the broadest

Lewis acid definition

Strong Acid

One that ionizes completely in aqueous solution. Strong electrolyte (HCl)

Examples of binary and oxyacids

Oxyacid: HClO = hypochlorous acid, HClO3 = chloric acid Binary: HCl = hydrochloric acid

pH

The concentration of hydronium ion's

pOH

The concentration of hydroxide ions

Titration

The controlled addition and measurement of the amount of a solution of known concentration required to react completely with a measured amount of a solution of unknown concentration

Lewis acid-base reaction

The formation of one or more covalent bonds between an electron pair donor and an electron pair of acceptor

Explain why the conjugate base of a strong acid is a weak base and the conjugate acid of a strong base is a weak acid

The general rules suggest that the stronger of a pair of acids must form the weaker of a pair of conjugate bases. The fact that HCl is a stronger acid than the H3O+ ion implies that the Cl- ion is a weaker base than water.

What is always true about the [H3O+] value of acidic solutions.

The pH of that solution will always be less than 7.

End point

The point in a titration at which an indicator changes color

Neutralization

The reaction of hydronium ion and hydroxide ions to form water molecules

What determines the extent to which a proton transfer reaction occurs

The weaker acid and base determine the extent to which a proton-transfer reaction occurs.

Self-ionization of water

To water molecules produce a hydronium ion and a hydroxide ion by transfer of a proton

Give an example of a substance or ion that has amphoteric characteristics

Water, amino acids, hydrogen carbonate ions and hydrogen sulfate ions

Weak base

Weak electrolyte

Strong base

Weak electrolyte (KOH)

What is the role of an indicator in a titration process

an indicator shows the chemical change

Will the value of [H3O+] in pure water change when the temp increases or decreases?

as temp increases, concentration of H3O+ increases