2.1.4 Acids Flashcards
Define an acid
Proton donors which release H+ ions in an aqueous solution
Define a base
Proton acceptors which relate OH- ions in an aqueous solution
What is an alkali
Soluble Base
Give examples of weak and strong acids
Weak acid = ethanoic acid
Strong acid = hydrochloric acid, nitric acid, sulphuric acid
Give examples of weak and strong bases
Weak bases = Ammonia
Strong bases = Sodium hydroxide, Potassium hydroxide
What does it mean if a acid is polyprotic and give me two examples
Donates more than one proton
Diprotic = Sulphuric acid
Triprotic = Phosphoric Acid
Hydrogen chloride + Lithium Hydroxide >
Lithium chloride + Water
How is Ammonia special when it comes to acid + base reactions ?
Doesn’t produce OH- ions directly it has to react with water first and accept a proton producing ammonium ions (NH4+) and hydroxide ions (OH-)
Calcium + Sulphuric Acid >
Calcium Sulphate + Hydrogen
A student plans to prepare 250cm2 of a 0.4000 mol dm3 solution of magnesium nitrate starting from magnesium nitrate crystals Mg(NO3)2 6H2O.
Describe how the student would prepare the solution giving full detail of quantities apparatus and method
Calculation
n = 250.0 × 0.4000 = 0.1(000) (mol)
Mass = 0.1000 × 256.3 = 25.63 g
Preparation steps (apparatus and method):
- Weigh mass of crystals using 2 or more decimal place balance
- Dissolve in deionised water
- Transfer to 250 cm3 volumetric flask and rinse beaker to transfer washings to flask
- Make up to the mark with more water so that
bottom of meniscus is on the mark
- Use of dropping pipette when filling to mark
-Stopper, invert several times to mix
Define a weak acid ?
Partially disassociates to release some H+ ions
Define a strong acid ?
Completely disassociates to release all H+ ions
Define a weak base ?
Partially disassociates to release some OH- ions
Define a strong base ?
Completely disassociates to release some OH- ions
