6. Acids and Bases Flashcards
What are the 4 types of oxides
Basic Oxide
Neutral Oxide
Acidic Oxide
Amphoteric Oxide
List 7 properties of Acids
- Tastes sour
- Turns blue litmus paper to red litmus paper
- Reacts with metals to form hydrogen gas
- Forms H+ Ions
- pH less than 7
- Neutralises bases
- Good conductors of electricity
List 5 properties of Bases
- Slippery, bitter
- Turns red litmus paper blue
- Usually forms OH- Ions
- Neutralises acids
- pH is greater than 7
How do acids react with metals?
acid + metal -> salt + hydrogen
Hydrochloric acid + base
Salts are chloride
For example:
Hydrochloric acid + Sodium hydroxide → Sodium chloride + Water
HCl+NaOH → NaCl+H₂O HCl+NaOH→NaCl+H₂O
Nitric acid + Base
Nitrates are formed
Example?
Sulphuric acid + Base
Sulphates are formed
Example?
How do acids react with bases? What products do they form?
Neutralise the base.
acid+base—> salt+water
How do acids react with metal carbonates?
Acid + metal carbonate –> salt + water + carbon dioxide
How to test for Hydrogen gas?
When a lighted splint is inserted, a pop sound is heard
2H2(g) + O2(g) -> 2H2O(l)
How to test for Carbon Dioxide gas?
When bubbled through limewater, the limewater turns cloudy
Lime water
Calcium Hydroxide Ca(OH)2
What is the product of lime water+ CO2
CaCO3, it is insoluble in water and thus becomes milky
Element reacting with Oxygen form?
Oxides
How to test for Ammonia?
Damp red litmus paper turns blue as ammonia is a weak base.
How to test for Oxygen?
Relights a glowing splint
How to test for Chlorine?
Bleaches damp blue litmus paper
Why??
Give 2 examples of strong acids
Hydrochloric Acid (HCl)
Sulfuric Acid (H2SO4)
2 examples of weak acids
Citric acid
Carbonic acid
Ethanolic acid (CH3COOH)
2 examples of strong bases
NaOH (Sodium Hydroxide)
KOH (Potassium Hydroxide)
Give 2 examples of weak bases
NH3 (Ammonia- cleaning product)
CH3NH2 (Methylamine- used in pesticides)
Basic Oxide
Form basic metal oxides which are generally ionic in bonding.
They react with acids to form salts
Neutral Oxide
Non-metallic oxides, no effect on litmus, do not reacted with alkalis or acids
Alkali
A base that dissolves in water
Acidic Oxide
In general non metals react with oxygen to make acidic oxides
* E.g. carbon burns in oxygen to make carbon dioxide
* Carbon dioxide dissolves in water to make carbonic acid
Example of Basic Oxide
Calcium Oxide (CaO)
Example of Neutral Oxide
Carbon monoxide (CO)
Nitric Oxide (NO)
Amphoteric Oxide
Metallic Oxides which react with acids and alkalis
Example of Amphoteric Oxide with reasoning
Aluminum Oxide as it dissolves in water to form ‘normal’ aluminum salts but it also dissolves in strong alkali like sodium hydroxide solution to form ‘aluminate’ salts
Amphoteric substance
A substance that can act as both an acid and a base
Example of an amphoteric substance
Water (H2O)
Universal Indicator
More specific pH value (universal indicator colour chart)
Acid = Red
Neutral = Green
Base = Purple
Litmus Indicator
Acid = Red
Alkali = Blue
Phenolphthalein Indicator
Acid= Colourless
Neutral= Light Pink
Base= Dark pink
Used in strong base-weak acid titrations
Methyl Orange Indicator
Acid= Red
Neutral= Yellow orange
Base= Yellow
Used in weak base-strong acid titrations
Apparatus for titration
Burette and Pipette and Conical flask
Soluble Salts making
acid+base
acid+metal
acid+metal carbonate
What is an Acid?
A compound that increases the concentration of hydrogen ion (H +) in aqueous solution
What is a Base?
A compound that increases concentration of hydroxide ions (OH -) in a water-based solution
Acidic Oxide example
SO2 (Sulphur Dioxide)
