2.1.4 Acids and 2.1.5 REDOX Flashcards
what happens when an acid is dissolved in water
the acid releases hydrogen ions as protons
Strong acid definition
releases all its hydrogen atoms into solution as H+ ions and completely dissociates in aqueous solution
example of strong acid
HCl
Weak acid definition
only releases some H+ ions so only partially dissociates in aqueous solution
example of weak acid
CH3COOH
what are bases
they neutralise an acid to form a salt
examples of bases
metal oxides
metal hydroxides
metal carbonates
ammonia
Alkali definition
a base that dissolves in water releasing hydroxide ions (OH-)
Acid + metal oxide or metal hydroxide
salt + water
Acid + alkali
Salt + water
Acid + carbonate
salt + water + carbon dioxide
Oxidation
gain of O2
loss of H2
loss of electrons
increase in oxidation number
Reduction
loss of O2
gain of H2
gain of electrons
decrease in oxidation numbers
Oxidation number definition
charge it would have if the bonding were totally ionic
Oxidation number rules
1) oxidation number of atoms in element is zero
2) oxidation number of ion is the same as the charge on the ion
3) sum of all oxidation numbers in a compound is zero
4) polyatomic ions the sum of all the oxidation numbers is equal to the charge on the ion
Making standard solution definition
wash 250cm3 beaker and 250cm3 volumetric flask
rinse glass rod and glass funnel
weigh mass of solid and boat
tip solid into beaker and reweigh bottle
add 100cm3 of water to beaker
stir with glass rod until dissolved
pour solution down glass rod into funnel into volumetric flask
rinse rod and beaker and pour into funnel
add distilled water until bottom of meniscus is on the mark
put stopper on and invert flask 15 times to uniform concentration throughout solution
