Transcript Acids, Bases, & Salts

Acids, Bases, & Salts
Chapter 25
Acids & Bases
Section 1
 Acids

contains at least 1 hydrogen atom that
can be removed when acid is dissolved
in water forming hydronium ions
 Properties
of acids
Taste sour
 Corrosive and can damage skin or
tissue
 React with an indicator such as litmus
paper to produce a predictable color
change

Common Acids
 Foods
contain acids.
 Citrus
fruits have citric acid.
 Yogurt and buttermilk have lactic
acid.
 Vinegar, or acetic acid, is in pickled
foods.
 The
stomach uses hydrochloric
acid.
Four acids are vital to industry.

Sulfuric acid


Phosphoric acid


used to make detergents, fertilizers, & soft
drinks.
Nitric acid


used in car batteries & in making fertilizers.
used to make fertilizers & explosives.
Hydrochloric acid

Used to clean steel
 Base
forms hydroxide ions in a water solution
 accepts hydronium ions from acids

 Properties
of bases
Crystalline solids in undissolved state
 Feel slippery in solution
 Strong bases are corrosive
 React with indicators to produce
predictable color changes; litmus paper
turns blue

 Uses

of Common bases
cleaning products, medications, fabrics,
and deodorants.
 Solutions
of acids and bases
Acid describes compounds that can be
ionized in water to form hydronium ions
 Base describes compounds that can form
hydroxide ions in solution
 Solutions of acids & solutions of bases
are electric conductors to some extent

Strength of Acids &
Bases
Section 2

strength of an acid or base


strong acid


only partly ionizes in solution.
strong base


ionizes almost completely in solution.
weak acid


depends on how completely a compound
separates into ions when dissolved in water
dissociates completely in solution.
weak base

does not ionize completely.
Strong acids and bases conduct more
electricity than weak ones.
 Equations for strong acids & bases use a
single arrow, indicating ions are formed
 Equations for weak acids & bases use
double arrows in opposite directions,
indicating an incomplete reaction
 Dilute and concentrated are terms to
describe the amount of acid or base
dissolved

 pH
- a measure of the concentration of
H ions in a solution or how acidic or
basic it is.
pH lower than 7 means acidic.
 pH greater than 7 means basic.
 pH exactly 7 indicates a neutral solution.

 pH
is determined using a universal
indicator paper or a pH meter.
 Blood contains buffers which keep the
pH balanced at about 7.4
Salts
Section 3

Neutralization


chemical reaction between an acid and a base
taking place in a water solution
Salt


compound formed when negative ions from an
acid combine with positive ions from base
also form when acids react with metals
Salt is essential for many animals
 Other salt uses


manufacturing of paint, rubber, glass, soap,
detergents, and dry cell batteries

Titration


used to determine the concentration of an acidic
or basic solution.
Process of Titration:
1. Standard solution
A
solution of known concentration
2. Indicator
 What
is added to the unknown solution.
3. End point
 When
a color change persists

Soaps




Detergents


form more soluble salts with the ions in hard water and
reduce soap scum; can cause other environmental
problems
Esters



organic salts with polar and nonpolar ends.
Nonpolar hydrocarbon end interacts with oil and dirt
Polar end helps oil and dirt dissolve in water
from alcohols, aren’t bases but have hydroxyl group
used in fruit flavorings and perfumes
Polyesters

synthetic fibers used to make fabrics