Chemistry - Acids, Bases and salts + redox

what is an alkali

releases OH- ions in aqueous solution

What is a strong acid?

an acid that fully ionises in a solution

what is a weak acid?

an acid that partially ionsis in a solution

what is ammonia

weak base

what is hydrochloric acid

a strong acid

acid + metal products

salt + hydrogen

metal oxide + acid products

salt + water

metal hydroxide + acid products

salt + water

metal carbonte + acid products

salt + water + carbon dioxide

what is the equation for moles

mass / Mr

what is the equation for concentration

moles / volume

what is volume measured in

dm3

recall the practical skills for titration ()

add the acid dropwise

remove the funnel when reading the burette

add up to 5 drops of chosen indicator

look at the meniscus when reading the volume

do a rough titration to find an estimate of acid

concordant results

white tile

swilling when acid tap is open

what are half equations

they show the transferance of electrons within a redox reaction

what is a redox reaction

a reaction that both oxidation and reduction occur

what is oxidation

loss of _ electrons

what is reduction

gain of _ electrons

oxidation number of oxygen

-2

oxidation number of hydrogen

what is a polyprotic acid

an acid that donates more than one proton H+

what is the oxidation number of a compound or pure element

0

equation to work out oxidation number

total charge = sum of know oxidation numbers + unknown

MnO4 - , oxidation number of Mn

-1 = Mn + (4*-2)

-1 -= Mn + -8

+7 = Mn

what is disproportionation?

where the same element is reduced and oxidised, it appears twice in the products

what are redcuing agents

cause reduction, but are oxidised

what are oxidising agents

cause oxidation, but are reduced

oxidation number of H in metal hydrides , HF

-1 , NaH

oxidation number of oxygen in hydrogen peroxide

-1

oxidation number of O when bonded with F

+2 , F is the most electronegative so it takes priority in terms of oxidation

give the likely range of iodine in oxidation states

group 7 , +7 to -1

give the likely range of phosphours in oxidation states

group 5 +5 to -3

what does an increase in oxidation numbers show?

oxidation

what does a decrease of the oxidation number show

reduction

half equations - if oxygen is present in products

add the according number of water

half eq1uations - how many H+ ions do you add

the same number, shown by the number of waters

combining half equations rule

make sure the number of electrons is the same in each, multiply by the lowest common multiple

what is the bond angle on a linear shape

180

what is the bond angle of a trigonal planar

120

what is the bond angle of a bent (V-shape) with one lone pair

118

what is the bond angle of a tetrahedral shape

109.5

what is the bond angle of a trigonal pyramid with one lone pair and 3 bonded pairs

107

what is the bond angle of a bent (V-shape) with two lone pairs

104.5

what is the bond angle of a trigonal bipyramidal

90

what is the bond angle of a trigonal pyramidal with 4 bonded pairs and one lone pair

89

what is the bond angle of a trigonal planar or T-shape with 3 bonded pairs and 2 lone pairs

120 or 89

what is the bond angle of an octahedral with 6 bonded pairs and 0 lone pairs

90

what is the bond angle of a square pyramid with 5 bonded pairs and one lone pair

89

what is the bond angle of a square planar with 4 bonded pairs and 2 lone pairs

90

what is electron repulsion theory

electron pairs repel each other as far away as possible

what is a lone pair

two electrons in a pair not involved in bonding

explain the shape around each carbon in ethene C2H4

trigonal planar, 3 bonded pairs 120

explain the shape around the carbon atom and oxygen in methanol

tetrahedral, around carbon atom as it has 4 bonded pairs and no lone pairs , 109.5, non linear around oxygen atoms as 2 bonding pairs