Acids + Bases (excl. Titrations) (2) Flashcards
Acid + Metal —> ____ + _______
Acid + Metal —> Salt + Hydrogen
Acid + Metal Hydroxide —> ____ + _____
Acid + Metal Hydroxide —> Salt + Water
Acid + Metal Oxides —> ____ + _____
Acid + Metal Oxides —> Salt + Water
Group 1 Metal + Water —> _____ _______ + ________
Group 1 Metal + Water —> Metal Hydroxide + Hydrogen
Acid + Carbonates —> ____ + _____ + ______ _______
Acid + Carbonates —> Salt + Water + Carbon Dioxide
Properties of Acids & Bases
Acids:
- Taste sour
- Turns litmus red
- Corrosive
- Molecular in structure
Bases:
- Taste bitter
- Turn litmus blue
- Feel slippery
Explain the Davy Theory on Acids + Bases
Acid:
- Substances containing replaceable hydrogen that could be partly or totally replaced by metals
Base:
- Substances that reacted with acids to form salts and water
Explain the Arrhenius Theory on Acids + Bases
Acids:
- Produces a hydrogen ion in solution
- HCl —> H^+ + Cl^-
Bases:
- Produces a hydroxide ion in solution
- NaOH —> Na^+ + OH^-
Explain the Bronstead-Lowry Theory on Acids + Bases
Acids:
- Substance that can donate a proton (hydrogen ion) in a reaction
Bases:
- Substance that can accept a proton (hydrogen ion) in a reaction
What are the disadvantages and advantages of the Bronsted Lowry theory?
Advantages:
- Isn’t limited to reactions in aqueous solutions
- Can include any reaction where acids donate proton to base
- HCL + NH3 —> NH4Cl
Disadvantages:
- Can’t be applied to reactions between acidic & basic oxides
- CaO + CO2 —> CaCO3
Show the conjugate acid-base pairs of: HCl H2SO4 HNO3 CH3COOH H3O^+ NH4^+ H2O
(From acid , base)
HCl:
- HCl , Cl-
- H3O ^+, H2O
H2SO4:
- H2SO4 , HSO4^-
- H3O^+ , H2O
HNO3:
- HNO3 , NO3^-
- H2O^+ , H2O
CH3COOH:
- CH3COOH , CH3COO-
- H3O^+ , H2O
H3O^+:
- H3O^+ , H2O
- H3O^+ , H2O
NH4^+:
- NH4^+ , NH3^-
- H3O^+ , H2O
H2O:
- H2O , OH-
- H3O^+ , H2O
What is an amphiprotic substance?
A substance which can function as either an acid or a base dependent upon what it is reacting with
E.g.
H2O
- Base: OH-
- Acid: H3O^+
HCO3^-
- Base: CO3^2-
- Acid: H2CO3
H2PO4^-
- Base: HPO4^2-
- Acid: H3PO4
What is monoprotic acid?
Can donate only 1 proton per molecule
E.g. HCl, HNO3, CH3COOH
What is diprotic acid?
Can donate 2 protons per molecule
E.g. H2SO4, H2CO3
What is polyprotic acid?
Can donate more than 1 proton per molecule
E.g. H2SO4, H3PO4, H2S, H2SO3
What is a triprotic acid?
Can donate 3 protons per molecule
E.g. H3PO4, H3BO3
What are strong acids?
- Molecules completely ionises in water
- Resulting solution: mainly ions and few molecules
E.g. only nitric acid (HNO3), sulfuric acid (H2SO4) & hydrochloric acid (HCL)
What are strong bases?
- Molecules completely dissociates in water
- Form separate ions (E.g. NaOH –> Na^+ + OH^-)
E.g. G1 & G2 hydroxides & oxides
What are weak acids?
- Molecules only partly ionise in water
- Resulting solution: consists of molecules and few ions
E.g. Vinegar + citric acid
What are weak bases?
- Molecules partially ionise in water
- Few ions formed
E.g. Ammonia
What is Ka?
The equilibrium expression is rearranged to give the acid/base dissociation equilibrium constant, which is a measure of the strength of acid/base.
Ka = products/reactants
E.g. HF + H2O –>
How do you determine if Carbonic acid (H2CO3) is a weak or strong acid (use hydrolysis)?
- H2CO3 + H2O —>
Is Ammonia (NH3) a weak or strong base (use hydrolysis)?
- NH3 + H2O —>
Define salts + examples
Is an ionic compound containing + ions other than a hydrogen ion or - ions other than the oxide ion or the hydroxide ion.
- E.g. CaCO3, FeSO4 & KF
What happens when a salt dissolves in water?
Completely dissolves in water and dissociates completely into ions
What is it called when one or both ions produced in dissociation can undergo a further reaction with water?
Hydrolysis
A salt formed between a strong acid and a strong base is ______
Neutral
A salt formed between a strong acid and a weak base is _______
Acidic
A sat formed in the reaction between a weak acid and a strong base is ______
Basic
Define buffer
- Are solutions that have the ability to resist pH change when small amounts of either acids or bases are added to them
- Generally contain a weak acid and its conjugate base OR a weak base and its conjugate acid
- They work as weaker acid + weak base can CO-EXIST in solution without neutralising one another but react to neutralise any strong acid or strong base added to buffer
Define buffer capacity
- The ability of a buffer solution to neutralise excess acid or base without a major change in pH
- Can be also defined as:
The amount of acid or base the buffer can neutralise before pH changes dramatically
