4A. Inorganic Chemistry and the Period Table [SET 1] Flashcards
How does ionisation energy change down group 2?
It decreases
Why does ionisation energy decrease down Group 2?
The extra inner shells shield electrons
Nucleus is further away from outer electrons due to more shells
How does reactivity change down group 2?
Reactivity increases
Why does reactivity increase down group 2?
It becomes easier for the outer electrons to be lost, as they have lower ionisation energies
What do group 2 elements react with?
Water, oxygen and chlorine
What are the group 2 elements?
Beryllium, Magnesium, Calcium, Strontium, Barium (Radium)
What do group 2 elements produce when they react with water?
Hydroxides and hydrogen
Which group 2 elements react with water?
All except Be, Mg reacts very slowly
What do group 2 elements produce when they react with oxygen?
Oxides
What colour are group 2 oxides?
White
What do group 2 elements produce when they react with chlorine?
Chlorides
What colour are group 2 chlorides?
White
Oxides and hydroxides are…
…bases
What happens when group 2 oxides dissolve in water?
They form a strongly alkaline solution due to OH-
What happens when beryllium oxide is added to water?
It doesn’t dissolve, it is insoluble
What happens when magnesium oxide is added to water?
It reacts slowly and isn’t very soluble
When oxides and hydroxides are added to acid, what do they form?
They neutralise the acid to form salts
What is the equation for the reaction between MgO and H2O?
MgO + H2O —-> Mg(OH)2
What is the equation for the reaction between MgO and HCl?
MgO + 2HCl —-> MgCl2 + H2O
Solubility trends of group 2 depend on…
…the anion
If a group 2 compound has a singly charged anion (OH-) how does the solubility change down the group?
It increases
If a group 2 compound has a doubly charged anion (SO4 2-) how does the solubility change down the group?
It decreases
Which group 2 sulfate is insoluble?
Barium Sulfate
How does thermal stability change down group 1 and 2 carbonates and nitrates?
It increases
Why do carbonates and nitrates become more stable down the group?
Large ions have less polarising power so distort the electron cloud less and have a lower charge density. Therefore, they distort the carbonate or nitrate less
Which of group 1 and group two compounds are more thermally stable?
Group 1
Why are Group 1 compounds more stable than group 2?
They have a lower charge, so a lower charge density and therefore less polarising power
What do group 2 carbonates decompose to form?
An oxide and carbon dioxide
What is the equation for thermal decomposition of CaCO3?
CaCO3 —-> CaO + CO2
Do group 1 carbonates decompose?
No
What do group 1 nitrates decompose to form?
The Nitrite (NO2) and oxygen
What is the equation for decomposition of Potassium nitrate?
2KNO3 —-> 2KNO2 + O2
What is the exception to the group 1 nitrate decomposition?
Lithium
What does lithium nitrate decompose to form?
LiO2, NO2 and O2