Acids and Bases Flashcards
What determines an acid’s strength?
The extent of its dissociation in an aqueous solution
Which nitrates are soluble?
All nitrates are soluble.
Which halides are soluble? (Cl-, Br-, I-)
All halides are soluble except Ag and Pb
Which sulfates are soluble?
All sulfates are soluble except Pb, Ba and Ca.
Which carbonates are soluble?
All are insoluble except Na, K and NH4
Which oxides are soluble?
All are insoluble except Na and K
Which hydroxides are soluble?
All are insoluble except Na, K and NH4 , with Ba and Ca being sparingly soluble.
Which phosphates are soluble?
All are insoluble except Na, K and NH4
What are basic oxides?
In first 3 groups of periodic table, also includes CuO and Fe2O3. Reacts with acids
What are acidic oxides?
Usually in last 3 groups of the periodic table includes CO2, SO2, SO3. Reacts with bases
What are amphoteric oxides?
Al, Zn and Pb. React with both acids and bases.
What are neutral oxides?
CO, NO and N2O. Do not react with acids or bases.
What method to use for preparation of insoluble salts?
Precipitation method:
- Add excess of one solution to the other, stir thoroughly
- Filter liquid to seperate precipitate
- Wash with DI water
- Dry with filter paper
What method to use for preparation of soluble salts?
Filtration method:
- Add excess of solution to warm dilute acid
- Filter to obtain filtrate
- Heat until pt. of saturation (crystallization etc.)
- Wash with small amount of cold DI water
- Dry between filter paper
What method to use for preparation of soluble salts (Group 1 or ammonium cation)?
Titration method:
1. Fill burette with dilute HNO3, note initial reading
2. Pipette 25.0cm3 of aqueous alkali into conical flask
3. Add 2-3 drops of methyl orange into conical flask
4. Add HNO slowly until end point is reached, where one drop turns colour of solution
5, Note the amount of acid required, repeat without indicator
6. Do crystallization, dry with filter paper, etc.
