4. Inorganic Chemistry & Periodic table Flashcards
Flame test colour for Lithium
Red
Flame test colour for Sodium
Orange/Yellow
Flame test colour for Magnesium
White/Colourless
Flame test colour for Calcium
Brick Red
Flame test colour for Strontium
Crimson Red
Flame test colour for Barium
Green
How are the positive flame colours produced?
When heat energy is absorbed by electrons some electrons will be promoted to orbitals which have higher energy.
The electrons will then drop back down to the original orbital they were in.
During this process they release energy some of which is in the form of light.
The flame colour produced depends on the wavelength of light energy emitted.
Explain the solubility of group 2 sulfates
-decrease in solubility as you go down the group
- magnesium sulfate is the most soluble and barium sulfate is the least soluble
Explain the solubility of group 2 hydroxides
- increases as you go down the group
- magnesium hydroxide is the least soluble and barium hydroxide is the most soluble
Describe the reaction is group 2 hydroxides with dilute acid.
Group 2 hydroxides will react with dilute acid to form a salt and water.
This is a type of neutralisation reaction
Reactions of group 2 with dilute acids
group 2 metals react with dilute acids to produce bubbles of hydrogen gas and solutions of metal compounds
Reaction of group 2 metals with water
Group 2 metals react with water in a redox reaction to produce a metal hydroxide and hydrogen.
The metal hydroxide forms as an alkaline solution hence why group 2 metals are known as the alkaline earth metals.
Reaction of group 2 metals with chlorine
Group 2 metals all react with chlorine gas to for metal chloride which are all white precipitate, as you move down the group. The reactions become more vigourous because the elements are more reactive.
Reaction of group 2 metals with oxygen.
Group 2 metals react with oxygen to form metal oxides.
Once the reaction has been initiated it is vigorous.
Barium can react with excess oxygen and heat energy to for metal peroxides.
Group 2 elements - Atomic radius
atomic radius increases down the group due to additional electron shells
Group 2 metals - Reactivity
Reactivity increases down the group as the electron shielding increases, and the increased atomic radius down the group makes the outer electron easier to lose
Group 2 metals - First Ionisation energy
First ionisation energy decreases down the group due to a greater atomic radius and increase shielding. This makes it easier for an electron to be removed.
