B9 Acids and Bases Flashcards
What is an acid
a substance that can form H+ (aq) ions or that is an H+ donor
List 6 common acids
HCL - hydrochloric H2SO4 - sulphuric HN03 - nitric H2CO3 - carbonic CH3COOH - ethanoic H3PO4 - phosphoric
What is the formula, strength, cation and anion associated with hydrochloric acid
HCL
Strong
H+
Cl-
What is the formula, strength, cation and anion associated with sulfuric acid
H2SO4
Strong
H+
SO4^2-
What is the formula, strength, cation and anion associated with nitric acid
HNO3
Strong
H+
NO3-
What is the formula, strength, cation and anion associated with carbonic acid
H2CO3
Weak
H+
CO3^2-
What is the formula, strength, cation and anion associated with ethanoic acid
CH3COOH
Weak
H+
CH3COO-
What is the formula, strength, cation and anion associated with phosphoric acid
H3PO4
Weak
H+
PO4^3-
What happens if an acid reacts with a metal
acid + metal = salt + hydrogen
What happens if an acid reacts with a base
acid + base = salt + water
What happens if an acid reacts with a carbonate
acid + carbonate = salt + carbon dioxide + water
What happens if HCl reacts with Mg
2HCl(aq) + Mg(s) = MgCl2(aq) + H2(g)
What happens if HCl reacts with NaOH
HCl + NaOH = NaCl + H20(l)
What happens if HCl reacts with Na2O
HCl + Na20 = 2NaCl + H20
What can be a base
metal hydroxide / metal oxide
What do we observe when an acid reacts with a metal
Metal dissolves > colourless solution. Effervescence is observed.
Colourless, odourless gas evolved extinguishes a lighted splint with a ‘pop’ sound.
What do we observe when an acid reacts with a soluble vs insoluble base
- Insoluble base: (white) solid dissolves to form a (colourless) solution
- Soluble base: no changes
What do we observe when an acid reacts with a carbonate
(white) solid dissolves to form a (colourless) solution.
Effervescence is observed.
Colourless, odourless gas evolved forms white precipitate in limewater.
What happens if HCl reacts with CaCO3
2HCl(aq) + CaCO3 (s) → CaCl2 (aq) + CO2(g) + H2O(l)
What is a base
a substance that can form OH– (aq) ions or that is an H+ acceptor
What is an alkali
a soluble base
What are general examples of bases
metal oxides and hydroxides
What are 4 common alkalis
sodium hydroxide
potassium hydroxide
calcium hydroxide
aqueous ammonia
What is the formula, strength, cation and anion associated with sodium hydroxide
Na0H
Strong
Na+
OH-
What is the formula, strength, cation and anion associated with potassium hydroxide
KOH
Strong
K+
OH-
What is the formula, strength, cation and anion associated with calcium hydroxide
Ca(OH)2
Strong
Ca2+
OH-
What is the formula, strength, cation and anion associated with aqueous ammonia
NH3 (aq) / NH4OH
Weak
NH4+
OH-
What is neutralisation
The reaction of an acid with a base can lead to neutralisation (a reaction between hydrogen ions and hydroxide ions to produce water)
What is the word equation for neutralisation
H+ (aq) + OH- (aq) → H2O (l)
What type of reaction is a neutralisation reaction
exothermic
What are oxides
compounds of oxygen with another element
What are the two types of oxides
metallic and non-metallic
What are the two types of metal oxides
basic oxides
amphoteric oxides
What are the two types of non metal oxides
acidic oxides
neutral oxides
What happens when acidic oxides react with water
React with water to form acidic solutions
What happens if sulfuric trioxide reacts with water
SO3 + H2O → H2SO4
What happens if acidic oxides react with bases/alkalis
• React with bases and alkalis to form salt and water
What happens if sodium hydroxide reacts with carbon dioxide
CO2 + 2 NaOH → Na2CO3 + H2O
How do basic oxides react with water
• React with water to form alkaline solutions
How do basic oxides react with acids
• React with acids to form salt and water
Are all metal oxides basic
*All metal oxides are basic except 3 amphoteric oxides
What are the three amphoteric oxides
zinc oxide, ZnO
lead (II) oxide, PbO
aluminium oxide, Al2O3
How do amphoteric oxides react with acids and alkalis
• React with both acids and alkalis to form salt and water
How do strong acids dissociate and ionise
• Strong acids dissociate / ionise completely in solution to give H+ ions.
How do weak acids dissociate and ionise
• Weak acids dissociate / ionise partially in solution to give H+ ions.
How do strong bases dissociate and ionise
• Strong bases dissociate / ionise completely in solution to give OH- ions.
How do weak bases dissociate and ionise
• Weak bases dissociate / ionise partially in solution to give OH- ions.
Define strength of a solution
extent of ionisation in an acid
fixed
Define concentration of a solution
- quantity of acid / alkali (solute) dissolved in the solution
- can be changed
What does pH measure
• Measures the acidity & alkalinity of a solution
What is the scale of pH
1 to1 4
What is pH based off of
• Based on concentration of H+ or OH- ions
What does a change in 1 of the pH scale correspond to
a change of 1 on the pH scale corresponds to a change by a factor of 10 in H+ ion concentration.
What are three examples of monoprotic acid
hydrochloric acid
nitric acid
ethanoic acid
What is one example of a diprotic acid
sulfuric acid
What is one example of a triprotic acid
phosphoric (V) acid
What can diprotic and triprotic acids form when reacting with bases
Diprotic and triprotic acids are able to form more than one type of salts when reacted with bases as they are able to form/donate more than one mole of H+ ions.
Write the word equations associated with sulfuric acid + Sodium hydroxide
H2SO4 (aq) + NaOH (aq) → NaHSO4 (aq) + H2O (l)
NaHSO4 (aq) + NaOH (aq) → Na2SO4 (aq) + H2O (l)
Write the word equations associated with phosphoric acid + Sodium hydroxide
H3PO4 (aq) + NaOH (aq) → NaH2PO4 (aq) + H2O (l)
NaH2PO4 (aq) + NaOH (aq) → Na2HPO4 (aq) + H2O (l)
Na2HPO4 (aq) + NaOH (aq) → Na3PO4 (aq) + H2O (l)