sc8, acids and alkalis (paper 1) Flashcards
acids have a pH of
less than 7
alkalis have a pH of
more than 7
acids are a source of what ions
hydrogen, H+
alkalis are a source of what ions
hydroxide, OH-
true or false: strong acids dissociate completely in water producing higher concentrations of H+ ions, whereas weak acids have incomplete dissociation
true
true or false: strong acids dissociate incompletely in water producing lower concentrations of H+ ions, whereas weak acids have complete dissociation
false
why can a dilute solution of a strong acid have a similar pH and reactivity as a concentrated weak acid
because they have a similar concentration of hydrogen ions
define neutralisation
an acid that reacts with a base to form a neutral substance
define base
a substance that neutralises an acid
true or false: all alkalis are bases, but not all bases are alkalis
true
true or false: all bases are alkalis, but not all alkalis are bases
false
what does a base + acid produce
salt + water
what does a metal + acid produce
salt + hydrogen
what does a metal carbonate + acid produce
salt + water + carbon dioxide
how do you test for hydrogen
a lighted splinbt ignites hydrogen with a pop
how do you test for carbon dioxide
turns limewater milky or cloudy white
are nitrates soluble or insoluble
soluble
are sodium, potassium and ammonium hydroxide soluble or insoluble
soluble
are sodium, potassium and ammonium carbonate soluble or insoluble
soluble
are common chlorides, sulfates soluble or insoluble
soluble
are sodium, potassium and ammonium salts soluble or insoluble
soluble
are silver and lead chloride soluble or insoluble
insoluble
are lead, barium and calcium sulfate soluble or insoluble
insoluble
are common hydroxides soluble or insoluble
insoluble
are common carbonates soluble or insoluble
insoluble
how is a precipitate formed
when you combine two aqueous solutions of soluble ionic compounds
define precipitate
an insoluble product
what colour is red litmus paper in acids
red
what colour is blue litmus paper in acids
red
what colour is methyl orange in acids
red
what colour is phenophthalein in acids
colourless
what colour is red litmus paper in alkalis
blue
what colour is blue litmus paper in alkalis
blue
what colour is methyl orange in alkalis
yellow
what colour is phenophthalein in alkalis
pink
