ACIDS AND REDOX Flashcards
WHAT IS AN ACID
A proton donor that releases H+ ions in aq solution
WHAT IS A STRONG ACID
an acid that fully dissociates in aqueous solution
WHAT IS A WEAK ACID
an acid that only partially dissociates in aqueous solution
WHAT IS A BASE
a proton acceptor that release OH- ions in aq solution
HOW IS A SALT FORMED
x3
a base and an acid
a metal and an acid
a metal and a non metal
WHAT IS AN OXIDATION NUMBER
the number of electrons lost or gained to or by a different element
WHAT IS REDUCTION
Decrease in oxidation number due to a gain of electrons
WHAT IS OXIDATION
Increase in oxidation number due to a loss of electrons
what is an alkali
a soluble base
Example of a weak acid
ethanoic acid or other carboxylic acids
(CH3COOH)
Example of strong acids and formula
Nitric acid (HNO3)
Sulphuric acid(H2SO4)
Hydrochloric acid(HCl)
Example of strong bases and formula
sodium hydroxide (NaOH)
Potassium hydroxide(KOH)
Example of a weak base
Ammonia(NH3)
What is a polyprotic acid and examples of mono, di, tri protic acids
An acid that can donate one or more proton
mono - Nitric acid (HNO3)
di - sulphuric acid (H2SO4)
tri - phosphoric acid (H3PO4)
example of formation of a salt from ammonia and an acid
2NH3(aq) + H2SO4(aq) –> (NH4)2 SO4(aq)
no water as by product
example equation and ionic equation for metal + acid
Ca(s) + H2SO4(aq) –> CaSO4(aq) + H2(g)
Ca(s) + H+(aq) –> Ca2+(aq) + H2(g)
Metal + acid –> ?
Salt + Hydrogen
example equation and ionic equation for metal oxide + acid
MgO(s) + 2HCl(aq) –> MgCl2(aq) + H2O(l)
MgO(s) + 2H+(aq) –> Mg2+(aq) + H2O(l)
Metal oxide + acid –> ?
Salt + water
example equation and ionic for metal hydroxide + acid
2NaOH(aq) + H2SO4(aq) –> Na2SO4(aq) + 2H2O(l)
2OH-(aq) + 2H+(aq) –> 2H2O(l)
metal hydroxide + acid –> ?
salt + water
Example and ionic equation for metal carbonate + acid
Li2CO3(s) + 2HNO3(aq) –> 2LiNO3(aq) + CO2(g) + H2O(l)
Li2CO3(s) + 2H+(aq) –> 2Li+(aq) + CO2(g) + H2O(l)
metal carbonate + acid –> ?
salt + carbon dioxide + water
How to set up and perform a titration
Add standard solution(known concentration) of acid or alkali into a burette
add unknown concentration of alkali or acid into conical flask below burette with a few drops of an indicator
titrate into conical flask and swirl until solution changes colour as it has reached the end point
record the titre value to 2 decimal places
repeat titration until you obtain concordant values
( within 0.10cm3 of each other)
How to prepare standard solution
Weigh the mass of solid precisely
transfer the solid into a beaker, rinsing weighing boat with deionised water
add deionised water and stir with glass rod until all solid has dissolved, then rinse glass rod into beaker with deionised H2O
transfer solution into volumetric flask and rinse beaker and funnel with deionised water
add deionised water to flask to reach graduation line
then mix solution by inverting flask multiple times
add this solution to burette for titration
OILRIG
oxidation is loss reduction is gain
What does a reducing agent do
it loses electrons and is in turn oxidised
what does an oxidising agent do
it gains electrons and is recued
standard oxidation states of :
- Uncombined elements
- ions
- group 1 elements
- group 2 elements
- Aluminium
- Hydrogen
- Chlorine
- Fluorine
- Oxygen
- always 0
- same as ion charge
- +1
- +2
- +3
- +1 (except in hydrides it is -1)
- -1 (except in compounds with F and O)
- -1
- -2 ( except with F or in peroxides it is -1)
