Acids and Bases

Question 1

bronsted-lowry acid

Answer 1

proton (H⁺​) donator

Question 2

bronsted lowry base

Answer 2

proton (H⁺​) acceptor

Question 3

conjugate acid base pairs

Answer 3

HA + B –> A^- + BH⁺

• conjugate acid-base pair
• conjugate acid-base pair

differ by one proton

Question 4

amphiprotic

Answer 4

• substance that can act as both a proton donator and a proton acceptor
• must have a lone pair of electrons and hydrogen that can be released as H⁺​

Question 5

alkali

Answer 5

bases that dissolve in water to form the hydroxide ion

Question 6

salt

Answer 6

• ionic compound formed when the hydrogen of an acid is replaced by a metal or another positive ion

Question 7

parent acid/base

Answer 7

e.g. NaCl derived from acid HCl and base NaOH

Question 8

acid + metal –>

Answer 8

salt + hydrogen

Question 9

acid + carbonate –>

Answer 9

• salt + water + carbon dioxide
• effervescence

Question 10

acid + base –>

Answer 10

salt + water

Question 11

Neutralization

Answer 11

• reaction that occurs when an acid and base react together to form salt and water
• exothermic

Question 12

enthalpy of neutralization

Answer 12

enthalpy change that occurs when an acid and a base react together to form one mole of water

Question 13

effervescence

Answer 13

gas given off so visibly produces bubbles

Question 14

acid-base indicators

Answer 14

change color reversibly according to concentration of H⁺ ions in the solution

Question 15

Why do acid-base indicators work?

Answer 15

• indicators are weak acids or bases whose conjugates have different colors
• color change identifies pH of substance
• usually aqueous or absorbed on test paper

Question 16

What is the sign of a good indicator?

Answer 16

gives distinct or sharp color change at equivalence point

Question 17

litmus

Answer 17

• best known acid-base indicator
• dye derived from lichens
• pink in presence of acid; blue in presence of alkalis

Question 18

universal indicator

Answer 18

• several indicators mixed together
• changes color many times across range of acids/alkalis
• can be used to measure [H⁺] on pH scale

Question 19

acid-base titration

Answer 19

• reacting together a carefully measured volume of one of solutions, and adding the other solution gradually
• until reach equivalence point

Question 20

equivalence point

Answer 20

where an acid and base exactly neutralize each other

Question 21

What is the pH equation?

What is the [H⁺] equation?

Answer 21

• pH = -log₁₀[H⁺]
• [H⁺] = 10^-pH

Question 22

What are some of the features of the pH scale?

Answer 22

• pH numbers usually positive
• have no units
• pH inversely related to [H⁺]
• change of one pH unit represents a 10-fold change in [H⁺]

Question 23

What are the values of pH?

Answer 23

Question 24

pH meter

Answer 24

• probe that directly reads [H+] through an electrode
• have accuracy to several decimal points
• must be calibrated before each use with buffer solution
• must be standardized for temperature

Question 25

ionic product constant of water

Answer 25

* K_w = [H+][OH^-] * in pure water [H+] = [OH^-​]

Question 26

Definitions of acidic, neutral, and alkali solutions by [H+]

Answer 26

* acidic solutions [H+] \> [OH^-] * neutral solutions [H+] = [OH^-] * alkaline solutions [H+] \< [OH^-]

Question 27

What is the relationship between [OH-] and [H⁺​]?

Answer 27

inversely proportional in aqueous solution

Question 28

strong acids/bases

Answer 28

* ionize almost completely in solution * hydrochloric acid, nitric acid, sulfuric acid * lithium hydroxide, sodium hydroxide, potassium hydroxide, barium hydroxide

Question 29

weak acids/bases and examples

Answer 29

* ionize only partially in solution * ethanoic acid, carbonic acid, phosphoric acid * ammonia, ethylamine

Question 30

How do you distinguish between strong acids/bases and weak acids/bases?

Answer 30

* strong acids/bases have higher concentration of ions than weak acids/bases * can only compare concentrations at same temperature

Question 31

electrical conductivity of strong/weak acids/bases

Answer 31

strong acids/bases have higher conductivity than weak acids/bases as long as same concentrations compared

Question 32

rate of reaction of strong/weak acids/bases

Answer 32

strong acids/bases have greater rate of reaction

Question 33

pH of strong/weak acids/bases

Answer 33

pH can be used to directly compare strengths of acids (as long as of equal molar concentration)