Acids and Bases Unit Flashcards
what is an electrolyte?
a substance which when dissolved, can conduct an electric current due to freely moving ions. both acids and bases are electrolytes, mainly ionic compounds
what is HCl?
an electrolyte and an acid
what is the arrhenius definition of acids
any substance which produces hydrogen ions that is the only positive ion in the solution
what is the modern interpretation of arrhenius’ def of acids
the positive ion formed is the hydronium ion
what are the properties of acids
- they are electrolytes
- they taste sour
- they react with metals to form hydrogen gas
- acids cause indicators to change color
- acids can neutralize bases
what is the arrhenius def of bases
a base is any substance which produces hydroxide ions as the only negative ion in the solution
what are the properties of bases
- they r electrolytes
- they taste bitter
- they feel slippery
- they cause indicators to change color
- they neutralize acids
what does the strength of an acid depend on
the strength of an acid solution depends not just on the molarity, but also the degree of ionization.
- it affects the number of hydrogen ions present in an aqueous solution of the acid and therefore the strength of the acid
what is pH
powers of hydrogen, it is a measure of the concentration of the H+ ions in a solution
if the H+ concentration is 1 x 10 ^-3 what is the pH
3
what does each step in the pH scale indicate
a ten times difference in concentration of H + ions
pH = 1 to pH = 4 is a thousand fold DECREASE
when pH increases, the number of hydrogen ions decreases
what will happen in any sample of water?
a small number of water molecules will ionize
- ionization constant of water = Kw
what are salts derived from
acids and bases, however, they do not produce H+ ions or OH- ions
what is hydrolysis
the reaction of the ions of the salt reacting with the ions from the self ionization of water molecules in the solution.
what are neutral salts produced by?
a strong acid and a strong base
why is there no attraction between the ions?
because the compounds have ionized completely or dissociated completely
why is it neutral?
with the ionization of water equilibrium remaining equal, ratios between H+ and OH- ions are the same, making the salt neutral
what are acidic salts produced from
formed from a strong acid and a weak base
why do the ions not react with eachother
there is little backwards reaction rate for a strong acid or a strong base due to the complete ionization of the compounds
what happens in a weak base or acid
the backwards reaction rate is stronger and the compounds will be reformed
what does this lead to
lesser concentration of either H+ of OH- ions whihc will lead to the solution being either more acidic or basic
how are basic or alkaline salts formed
they are formed from a strong base and a weak acid
eg: NaOH and HCH3COO
what will happen to the NaOH
it will dissociate completely into Na+ and OH- ions , no attraction between the two
what will happen to the HCH3COO
the ions produced will joined together, so there is a lesser concentration of H+ ions, therefore the solution is basic/alkaline
what is the outcome of the salts of a weak acid and a weak base
it could be a weak acid or base depending on the parent acid/base
what is a salt
an ionic compound which produces any positive ion other than hydrogen and any negative ion other than hydroxide when dissolved in water
what is the titration equation
MA x VA = MB x VB
what is the Bronsted-Lowry acid and base theory
an acid is any substance which donates a proton in a chemical reaction
a base is any substance which accepts a proton.
what is amphoteric(amphiprotic)
a substance which can act as either an acid or a base
what is a strong acid’s conjugate
a weak base, and vice versa
