Atomic Structure Flashcards
What are the properties of an acid?
_ All acids contain Hydrogen _ Turns blue litmus red _ All acids are solutions _ Strong acids completely ionize when dissolved in water while weak ones only partially
What are the properties of a base?
_ All base is a metal oxide
_ Turns red litmus blue
_ An alkali is a soluble base, a metal hydroxide
_ All alkalis are solutions
_ All alkalis completely ionize when dissolved in water
while weak ones only partially
Acid + Metal = ?
Acid + Base = ?
Acid + Alkali = ?
Acid + Metal Carbonate = ?
Acid + Metal = Salt + Hydrogen
Acid + Base = Salt + Water
Acid + Alkali = Salt + Water
Acid + Metal Carbonate = Salt + Water + Carbon Dioxide
Base + Acid = ?
Base + Ammonium Salt =?
Base + Acid = Salt + Water
Base + Ammonium Salt = Salt + Water + Ammonia
What is the meaning of Strong and Weak acids?
Strong acids are completely ionized in aqueous solutions (lots of H+ ions released)
Weak bases only partially ionize in aqueous solutions (fewer OH- ions released)
what color is methyl orange in acid and alkali?
Acid - Red
Alkali - Yellow
What do Acids Produce in an aqueous solution?
H+ Ions
What do bases produce in an aqueous solution?
OH- Ions
Describe acids and bases in terms of protons
H+ ions are protons
Acids are Proton Donors
Bases are Proton Acceptors
What is the difference between strong and weak bases?
Strong bases completely ionize in aqueous solutions (lots of OH- ions released)
Weak bases only partially ionize in aqueous solutions (fewer OH- ions released)
Why is it important to control the acidity in soil?
If the soil is too acidic, crops will be unable to grow
What are some amphoteric oxides
- Aluminium oxide
- lead(II) oxide
- Zinc oxide
What are the physical properties of metals?
_ Good conductor of heat and electricity _ Shiny _ Malleable _ Sonorous _ Ductile _ Usually have high melting and boiling points _ High density (Except group I)
What are the chemical properties of metals?
_ Usually form basic oxides (bases)
_ Form positive ions
_ React with acid to form salt and hydrogen
_ React with non-metals forming ionic bonds
Why are alloys used over metals?
Because they have properties of the metal used. So we can modify the properties by mixing it with other metals
What is the structure of alloys
Regular rows of positive ions (Cations) and is surrounded by delocalized mobile valence “sea of electrons”
Explain what happens in reduction and oxidation
Oxidation:
- Gain of oxygen
- Loss of Electrons
- Loss of Hydrogen
Reduction:
- Loss of Oxygen
- Gain of Electrons
- Gain of Hydrogen
what is a redox reaction?
A reaction where oxidation and reduction happens at the same time
How can metals be extracted from their ore
Reduction with carbon: Only possible if the metal is less reactive than carbon
Electrolysis: Can be done with all metals but require a large amount of energy
How can iron be extracted from its ore, hematite
- Iron, coke, and limestone is added through the top
- Hot air enters through the bottom and moves to the top
- CO is formed by a reaction between Coke and Oxygen
- CO reduces Iron oxide to Iron
- CO gets oxidized to Carbon Dioxide
- Molten iron pours out through the bottom
Write a balanced equation for the reduction of iron
2Fe2O3 + 3C = 4Fe + 3CO2
Why is limestone added and what are its reactions
Limestone (CaCO3) thermally decomposes to form calcium oxide, calcium oxide then reacts with the sand in hematite (Silicon oxide) to form Calcium silicate (slag). Slag is used to make roads and cement.
How can iron be converted to steel
Iron contains 4% carbon impurities, Steel contains 1%. In order to remove the carbon impurities, oxygen is blown onto the molten iron. Oxygen reacts with excess carbon to form CO and CO2 which escape. Oxygen also reacts with the impurities in iron to form acidic oxides. These are removed using calcium oxide
How do we extract zinc from zinc blende?
Zinc blend cannot be reduced by carbon, but zinc oxide can. So zinc blende is roasted in the air and reacts with oxygen to form zinc oxide and sulfur dioxide. This zinc oxide then is reduced by carbon and you get zinc and Carbon monoxide because Carbon is oxidized
What is electrolysis?
Electrolysis is The breakdown of molten or aqueous ionic compounds using electricity
What is a cathode and anode?
Cathode - Attracts negative ions
Anode - Attracts positive ions
What will form at the cathode?
If hydrogen is more reactive than the metal, then hydrogen will be formed. If it is less reactive than hydrogen, then the metal will be formed
What forms at each electrode during the electrolysis of dilute sulfuric acid
Positive electrode: Oxygen
Negative electrode: Hydrogen
How can the products of molten electrolytes be predicted?
Anode electrode: non-metal
Cathode electrode: metal
What are some reasons for electroplating?
- Increase resistance against corrosion
- Improve appearance
Compare the movement of electrons to the movement of ions
Electrons move through the metallic conductor meaning they move from the positive electrode to the negative.
While ions move through the electrolyte
Where does oxidation and reduction happen and why?
Reduction happens in the cathode because this is where positive ions gain electrons, electrons move from anode to cathode so oxidation happens in the anode because the anode takes electrons from negative ions
what is the order of reactivity?
Potassium, Sodium, Calcium, Magnesium, Aluminium, Carbon, Zinc, Iron, Hydrogen
what is the bonding in diamond, graphite, and silicon dioxide?
Covalent bonds
Properties of Diamond and silicon dioxide
- Poor electrical conductor
- High melting point
- Hard
- Insoluble
Properties of Graphite
- Lubricant
- Good electrical conductor
- Soft and Slippery
what are ionic bonds?
electrostatic attraction between oppositely charged ions
what are 3 chemical properties of transition metals?
- good catalysts
- variable oxidation numbers
- form coloured compounds / coloured ions
What is the structure of solids, liquids and gases?
Solids are tightly packed and close together in a regular arrangement. They vibrate about a fixed point
Liquids are still close together but have a random arrangement. The particles slip and slide over each other in a continuous random motion
Gases have large distances between particles and have random arrangements. They move in a continuous rapid random motion
How do you calculate Rf value?
Solvent font
How can you tell if a substance is pure from its boiling point
A pure substance melts and boils at a fixed temperature if the melting and boiling point is a range, then it is impure.
What are the properties of Ionic compounds?
- Conducts electricity when molten or dissolved in a solution - High melting and boiling point - Soluble in water - Brittle
In electroplating which electrode will be plated and plating?
Object to be plated - Cathode
Metal used to plate - Anode
