Acids & Bases Flashcards
What is the arrhenius definition of an acid?
susbtances the produce H+, or H3O+ in aqueous solution
What is the arrhenius definition of a base?
substances that produce OH- in aqueous solution
What is the Bronsted-Lowry definition of an acid?
a proton (H+) donor
What is the bronsted-lowry definition of a base?
a proton (H+) acceptor
What are amphoteric substances? Examples?
substances that can act as either an acid or a base
H2O, H2PO4-, bicarbonate, amino acids
What is a conjugate acid-base pair? Examples?
consists of two substances that differ only by the presence of a proton
H2O is conjugate acid of OH-, OH- is conjugate base of H2O
What is the conjugate base of HCO3- if it reacts with water? What about the conjugate acid?
CO3-
H2CO3
What is the general equation for an acid reacting in water?
HA + H2O –> H3O+ + A-
If you put one mole of a strong acid into water what are the expected products?
would completely ionize (dissociate) and you would get one mole of H3O+ and one mole of the corresponding anion
What are some examples of strong acids?
hydrochloric acid (HCl), hydrobromic acid (HBr), Hydroiodic acid (HI), Nitric acid (HNO3), Perchloric acid (HClO4), Sulfuric acid (H2SO4)
If you put one mole of a weak acid into water what do you think will happen?
only partially ionize, amount that will ionize is reflected by the Ka value
What is the formula for Ka? What is ingored in this formula, why is it ignored?
Ka=[A-][H3O+]/[HA]
water, because its a solvent with a constant concentration
How can you tell which weak acid is stronger?
higher Ka means stronger and lower pka means stronger
What is the general equation for a base reacting in water?
NaOH + H2O –> Na+ + OH-
What are some strong bases?
sodium hydroxide (NaOH), lithium hydroxide (LiOH), potassium hydroxide (KOH), strontium hydroxide (Sr(OH)2), calcium hydroxide (Ca(OH)2), barium hydroxide (Ba(OH)2)
What is the formula for Kb? What is ignored and why?
Kb=[BH+][OH-]/[B]
water, because its a pure solvent
How can you tell which weak base is stronger?
bigger Kb, means stronger as well as smaller pKb
What is the autoionization of water?
when water acts as an acid and a base by transfering a proton to another water
What is the the Kw constant?
Kw=[H3O+][OH-]=1.0x10^-14
How can you calculate the concentration of OH- using H3O+ concentration and Kw?
[OH-]=Kw/[H3O+]
How can you calculate pH?
pH=-log[H3O+]
What pH is basic, acidic, or neutral?
basic is greater than 7, acidic is less than 7, neutral is 7
How can you calculate pOH?
pOH=-log[OH-]
What equation can you use to find pH if you know pOH and vice versa?
pOH + pH = 14
How can you calculate [H+] if you know pH?
10^-pH
How can you calculate pKa and pKb?
pKa=-log(Ka)
pKb=-log(Kb)
How can you find the pKa of a conjugate base pair if you know pKb and vice versa?
pKa + pKb = 14
only for conjugate acid-base pairs in water
How can you calculate Ka or Kb if you know the other of a conjugate acid-base pair?
Kb x Ka = Kw
How can you find pH of a weak acid/base?
ICE tables
What is the formula for % ionization of a weak acid?
=[H3O+]/(initial acid concentration) x 100
WHat is a general formula to find % ionization?
= square root (Ka/Ca) x 100
If there is a mixture of acids, when can we find the pH?
if one acid is much stronger than the others, can ignore the other acids
What is the properties of ions and salts for anions?
anions that are the conjugate base of a weak acid is itself a weak base, and anions that are the conjugate base of a strong acid is pH-neutral
What is the properties of ions and salts for cations?
A cation that is the conjugate acid of a weak base is itself a weak acid, a cation that is the conjugate acid of a strong base is pH-neutral
What are polyprotic acids?
can donate more than one proton
If the Ka of the 1st proton for a polyprotic acid higher than the subsequent ones, why?
yes
the removal of a second and third H+ involves a separation of a positive charge (H+) from a negatively
charged anion, which are attracted by coulombic forces.
How can you find the volume of a certain acid/base to make a solution with a certain pH and volume?
Find concentration of H+ or OH- (10^-pH or 10^-pOH)
Multiply that by the volume
Divide that by the concentration of the acid/base
