MAIN POINTS Flashcards
Conversion of States of Matter
Solid to Gas: Sublimation
Gas to Solid: Deposition
Liquid to Gas: Vaporisation
Gas to Liquid: Condensation
Solid to Liquid: Fusion
Liquid to Solid: Solidification
Heterogenous Mixtures Types
Suspensions: Solute particles do not get dissolved in the solvent
Ex. Mud Water
Colloids: Mixtures that scatter light but don’t settle out.
Ex. Milk
Emulsions: Two immiscible liquids
Ex. Paint
Properties of Periodic Table
Properties of Group 1: Alkali Metals
-Highly Reactive, Low m.p. & b.p.
Properties of Group 2: Alkaline Earth Metals
-Less reactive compared to alkali but still very reactive, Higher m.p. & b.p. than alkali metals
Properties of Group 5: Transition Metals
High m.p. & b.p, Act as catalyst in reactions
Properties of Group 7: Halogens
-Highly reactive, Non metals
Properties of Group 18: Noble Gases
-Inert reactivity
-Very low b.p. and m.p.
Specific heat capacity
The amount of energy required to increase the temperature of 1kg of a substance by 1 degrees C
Endothermic and Exothermic
What type of reaction is it if heat absorbed during reaction? (-Delta H): Endothermic
What type of reaction is it if heat absorbed during reaction? (+Delta H): Endothermic
Soluble Salts Making
acid + metal –> salt + hydrogen gas
acid + metal carbonate –> salt + carbon dioxide + water
acid + insoluble base (metal hydroxide or oxide) –> salt + water
Tests for hydrogen gas, chlorine, carbon dioxide, oxygen, ammonia
Chlorine: Bleaches damp blue litmus paper
Hydrogen gas: When a lighted splint is inserted, a pop sound is heard
Oxygen: Relights a glowing splint
Carbon Dioxide: When bubbled through calcium hydroxide, CaCO3 is formed which is insoluble in water
Ammonia: Damp red litmus paper turns blue as ammonia is a weak base.
Examples of Acids and Bases
Strong Acids:
HCl –> Hydrochloric Acid
H2SO4 –> Sulphuric Acid
Weak Acids:
Citric acid
Carbonic acid
Strong Bases:
KOH –> Potassium Hydroxide
CNaOH –> Sodium Hydroxide
Weak Bases:
NH3 –> Ammonia
CH3NH2 –> Methylamine
Factors Affecting Equilibrium
Temperature: If you increase the temperature of an already existing exothermic reaction it will become an endothermic reaction
Pressure: If you increase the pressure, the number of particles per unit volume increases.
Increasing- Equilibrium will shift where number of gaseous particles are less.
Decreasing- Equilibrium will shift where number number of gases are more.
Concentration:
If concentration of reactants/ if concentration of products is decreased, it will shit towards the forward direction
Catalyst:
If catalyst is added, it will impact forward and backward reaction in the same manner, equilibrium will be achieved faster
Types of Oxides
Amphoteric: Metallic Oxides which react with acids and alkalis
Basic: Form basic metal oxides which are generally ionic in bonding and they react with acids to form salts
Neutral: Non-metallic oxides, no effect on litmus, do not reacted with alkalis or acids
Acidic: Non metals react with oxygen to make acidic oxides
Equilibrium
Needs to be a closed system. When the rate of forward reaction is equal to the rate of the backward reaction in a reversible reaction, equilibrium is achieved
Types of Indicators (4)
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
Oxidation and Reduction
Oxidation:
Gain of Oxygen
Loss of Hydrogen
Loss of electrons
The substance which oxidizes is the reducing agent/ reductant
Reduction:
Loss of Oxygen
Gain of Hydrogen
Gain of electrons
The substance (reactant) which reduces is the oxidizing agent/ oxidant
Electrod in Electrolysis
Cathode and Anode
Cathode attracts cations (+)
Anode attracts anions (-)
Is a rod of metal or graphite through which an electric current flows into or out of an electrolyte
Oxidation Rules (6)
Uncombined Element: 0
Simply Ions: Valency
Elements in a compound: =0
Polyatomic Ion= Sum = Charge
Hydrogen = +1 (except metal hydrides where it is -1)
Oxygen: -2
Salt Bridge in Voltaic Cell
1) The salt bridge helps to maintain the neutrality of the solution.
2) Movement of ions (cation to cathode and anion to anode) takes place via the salt bridge.
A salt bridge will contain metal salts as they are higher on the reactivity series and they would not interfere with the movement of ions.
Ex. of salts which can be used:
KNO3 (potassium nitrate)
NaNO3 (Sodium nitrate)
Site of oxidation and reduction in voltaic cell
Oxidation is at Anode
Reduction is at Cathode
Factors affecting Voltaic cell
Electrode Material: The more easily a metal loses electrons, the higher the voltage
Zinc- as the anode
Copper- as the cathode
Electrolyte Concentration: Increased ion concentration in the electrolyte enhances the rate of chemical reactions, leading to higher voltage
Temperature: Higher temperature leads to a lower voltage due to higher internal resistance
Surface Area of Electrodes: Larger surface area: Greater contact between electrodes and electrolyte, faster
reactions, higher voltage
