Reactions of acids with bases
properties of bases
-bitter taste -dilute aqueous solutions feel slippery -change the color of dyes known as acid-base indicators -react with acids to form salts and water -electrolytes
neutralization
-reaction between H3O+ and OH- to form water molecules -all acid and base properties disappear
strong bases
-strong electrolytes -strength is based on the extent in which it dissociates and adds hydroxide ions to the solution
neutralization reactions
-traditional acid-base reactions -reaction in aqueous solution between an acid that produces hydronium and a hydroxide-producing base
Causes of controlling soil acidity
- acid rain - bacteria and fungi rotting the vegetation so that it releases acids - use of fertilisers containing ammonium salts
NaOH + H₃PO₄
3NaOH + H₃PO₄ → Na₃PO₄ + 3H₂O
Reacting ammonium sulfate with an alkali
- warm a solution of an ammonium salt w/ sodium hydroxide solution (gas given off) - test with damp red litmus paper - paper turns blue ( shows that an alkaline gas is present) ammonia
traditional definition for bases
-based on the observations of Arrhenius -substance that contains hydroxide ions and dissociates to give hydroxide ions in aqueous solutions
stronger acid
weaker conjugate base
Al₂O₃ + NaOH (hot, conc) + H₂O
Al₂O₃ + 2NaOH + 3H₂O → 2NaAl(OH)₄
Al₂O₃ + HCl
Al₂O₃ + 6HCl → 2AlCl₃ + 3H₂O
MgO + HCl
MgO + 2HCl → MgCl₂ + H₂O
Na₂O + H₂SO₄
Na₂O + H₂SO₄ → Na₂SO₄ + H₂O
SO₂ + NaOH
SO₂ + 2NaOH → Na₂SO₃ + H₂O
SiO₂ + NaOH
SiO₂ + 2NaOH → Na₂SiO₃ + H₂O
Define universal indicator
a mixture of indicators which shows a range of colour depending
Define alkali
a soluble base that releases OH- ions in aqueous solution e.g. NaOH, CA(OH) , NH
Define base
a substance that can react with an acid
Define acid
a substance that produces hydronium ions when it dissolves in water e.g. HCL, H SO , HNO
Al₂O₃ is an ___ oxide because
amphoteric, it reacts with both acids and alkalis
Lewis
an atom, ion, or molecule that is an electron pair donor and forms a covalent bond
amphoteric
any substance that can react as either an acid or a base
Define reversible reactions
chemical reaction in which the products reform the original reactants
alkaline solutions
contain OH-
H₃PO₄ reacts with NaOH in 3 stages because
it has 3 OH groups, each H⁺ in the OH⁻ group reacts in turn and is replaced
Bronsted-Lowry
molecule that is a proton acceptor
Define redox reactions
reaction in which reduction + oxidation have taken place together
Na/Mg oxide + acid --->
salt + water
Reaction of acids with carbonates
salt + water + carbon dioxide
conjugate acid
substance formed when a Bronsted base gains a proton
conjugate base
substance that remains after a Bronsted acid has given up a proton
Define oxidation
the gain of oxygen (loss of electrons)
Define reduction
the loss of oxygen (gain of electrons)
SiO₂ reacts as a ___ with ____
weak acid, strong bases
weak bases
weak electrolytes
stronger base
weaker conjugate acid
