Chapter 10 - Acids and Bases

CHEM:1070 Final Exam

what are some properties of acids?

• have a sour taste

• have a stinging feeling

• neutralize bases

• corrode some metals

what are some properties of bases?

• have a bitter taste

• have a soapy feel

• neutralize acids

what is the rule for naming acids with a hydrogen ion and nonmetal?

use the prefix hydro and end it with ic acid

what is the rule for naming acids with a hydrogen ion and a polyatomic ion that ends with -ate?

only end with ic acid

what is the rule for naming an acid with a hydrogen ion and a polyatomic ion ending with -ite?

end it with -ous acid

what is one exception to for naming?

HCN is named hydrocyanic acid

what is the rule for naming bases?

they are typically named with the second name being hydroxide

what are monoprotic acids?

they only have one reactive H+ that can be donated

what are diprotic acids?

they have two reactive H+ bases they can donate

what are triprotic acids?

have three reactive H+ that can be donated

what is the definition for arrhenius acids?

they produce hydrogen ions when dissolved in water

what is the definition for arrhenius bases?

they produce hydroxide ions when dissolved in water

what is the bronsted-lowry definition of acids?

they donate hydrogen ions when dissolved in water

what is the bronsted-lowry definition of bases?

they accpet hydrogen ions when dissolved in water

what is a conjugate acid-base pair?

they are related by loss and gain of electrons

what is an amphoretic substance?

it is a substance that have the capability to act as both acids and bases

• so when met with a stronger acid it accepts a H+

• and when met with a stronger bas it donates a H+

what is a strong acid?

it completely dissociates into ions in aqueous solutions so therefore they’re strong electrolytes

what does a single arrow represent?

that there is complete ionization

what are the six common acids?

• HCl

• HBr

• HI

• HNO3

• HClO4

• H2SO4

what is a weak acid?

it dissociates partially to form a few ions therefore it is a weak electrolyte

what does a double arrow represent?

it indicates partial ionization

what are some examples of weak acids?

• HF

• HCN

• H2CO3

• H3PO4

• HNO2

what happens to a strong acid in water?

there are only ions of the molecule dissolve no leftovers

what happens to a weak acid in water?

there are only few ions of the molecule dissolved but then some leftover molecule that wasn’t able to be dissolved

what is a strong base?

it completely dissociates into ions in an aqueous solution

what are some examples of strong bases?

• LiOH

• NaOH

• KOH

• RbOH

• CsOH

• Ba(OH)2

• Sr(OH)2

• Ca(OH)2

what are weak bases?

ionizes only partially in water and forms a few ions

what are some examples of weak bases?

• Mg(OH)2

• Al(OH)3

• NH3

• organic compounds containing nitrogen

• Na2CO3

• CaCO3

• NaHCO3

what is the equation of a conjugate acid-base reaction?

acid + base —> < -— conjugate base + conjugate acid

what does the reactant acid pair with in the CAB reaction and what does it do?

it is paired with the conjugate base, which loses an hydrogen

(Ex. HF(acid) —> F-(conj. base)

what does the reactant base pari with in the CAB reaction and what does it do?

it is paired with the conjugate acid, which gains an hydrogen

(Ex. H2O(base) —> H3O+)

what happens to the conjugate base of acid as the strength of the acid increases?

the conjugate base decreases

what direction does an aqueous acid-base reaction go in?

AR favor the direction that goes from stronger chemical species to weaker chemical species

what is the equation for the constant equilibrium?

Kc, Kb, Ka = [products]/[reactants] and liquids and solids are not included

what side does the equilibrium favor if Ka or Kb is less than 1?

it favors the reverse reaction and so there are more reactants

what side does the equilibrium favor if Ka or Kb is more than 1?

the equilibrium favors the forward reaction, so then there are more products

how does the Ka affect the strength of the acid?

the larger the Ka, the stronger the acid

how does the Kb affect the strength of a base?

the larger the Kb, the stronger the base

what is the formula for pKa?

pKa = -log(Ka)

what makes the acid stronger in terms of Ka?

the larger the Ka value, the stronger the acid

what makes the acid stronger in terms of kPa?

the smaller the pKa, the stronger the acid

what is the equation for the water dissociation constant?

Kw = [H3O+][OH-]

what is the value of Kw?

1.0 × 10^-14 at 25 C

what is the solution when [H3O+] and [OH-] are equal?

the solution is neutral

what is the solution when [H3O+] is greater than [OH-]?

the solution is acidic

what is the solution when [H3O+] is less than [OH-]?

the solution is basic

what is the pH scale?

a logarithmic scale used to describe the acidity or basicity of solutions

what is the equation of the pH scale>

pH = -log[H3O+]

why is the pH scale is a negative log scale?

a change of one pH unit corresponds to a tenfold change in [H3O+] and pH decreases as the [H3O+] increases

when is a pH of a solution acidic?

when the values are less than 7, [H3O+] > 1×10^-7 M

when is a pH of a solution neutral?

when the pH is 7, [H3O+] = 1×10^-7 M

when is the pH of a solution basic?

when the values are greater than 7, [H3O+] < 1×10^-7 M

How do you calculate [H3O+] from pH?

[H3O+] = 10^-pH

what do acids react with?

• bases to produce a salt and water

• metals to produce a salt and hydrogen gas

• bicarbonate and carbonate ions