MODULE 2 -2.1.4 acids Flashcards
What are acids?
Proton donors (H+)
What are bases?
Proton acceptors
What happens when acids and bases react?
Forms a reversible reaction
What is an alkali?
A soluble base that produces -OH ions
Give an example of a weak acid
Ethanoic acid (CH3COOH)
Give an example of a strong acid
HCl, H2SO4, HNO3
Give an example of a strong base
NaOH, KOH
Give an example of a weak base
NH3
Polyprotic acids
Acids that can donate more than one proton e.g HNO3 is monoprotic (1 mol of H+), H2SO4 is diprotic (2 mol of H+), H3PO4 (3 mol of H+),
What are salts?
Neutral compounds formed from acid and bases
Equation for metals and acid
METAL + ACID -> SALT + HYDROGEN
Equation for metal oxides and acids
METAL OXIDE + ACID -> SALT + WATER
Equation for metal hydroxides and acids
METAL HYDROXIDE + ACID -> SALT + WATER
Equation for metal carbonates and acids
METAL CARBONATE + ACID -> SALT + CO2 + WATER
The mole equation for solutions
n = concentration (moldm-3) x volume (dm3)
What are titrations used for?
Finding out the concentration of an acid of alkali
How do you carry out a titration?
- Have an acid/alkali with a known concentration in a burette
- Add the chemical in the burette to the conical flask until UI changes colour (end point)
- Add drop by drop
- Add an acid/ alkali with an unknown concentration but known volume into conical flask and UI
- Read how much chemical was added from the burette to neutralise the chemical.
- Read bottom of meniscus at eye level
- Record results to 2dp to get concordant results
How do you make standard solutions?
- Weigh the amount with balance
- Transfer solid to beaker
- Dissolve solid with water and stir
- Transfer to volumetric flask with funnel. Rinse beaker and glass rod
- Fill water to graduation line and use pipette if needed
- Invert flask and put lid onto ensure thorough mixing
