Chapter 4 Flashcards
What happens to ionisation energy as you go down the group?
It decreases
Why does the ionisation energy decrease as you go down the group?
- Each element has an extra electron shell
- Extra shells shield attraction from the nucleus
- Outer electrons are further away from the nucleus
As ionisation energy decreases down the group, why does this mean that the reactivity in group 1 increases as you go down the group?
It is easier for the elements to lose their outer electron when they react and form a +1 ion.
What ions do group 2 elements form?
+2 ions
When group 2 elements react with water, what do they form?
Metal hydroxide + hydrogen
What is the chemical formula of calcium hydroxide?
Ca(OH)2
When group 2 elements burn in oxygen, what is the only product formed?
Solid white oxides
What is the chemical formula of calcium oxide??
CO
When group 2 elements react with chlorine, what do they form?
Chlorides
What is the chemical formula of calcium chloride?
CaCl2
Why are metal hydroxides strongly alkaline?
Because of the OH- ions
Are the oxides of he group 2 elements soluble?
Yes, and it increases as you go down group 2
Why do the group 2 oxides form more strongly alkaline solutions as you go down the group?
Because the hydroxides get more soluble
As they are bases, what are the oxides and hydroxides of group 2 metals able to do?
Neutralise dilute acids, and form salts
When metal hydroxides react with water, what do they form?
Metal hydroxides
When metal oxides react with dilute HCl, what do they form?
Metal chlorides and water
When metal hydroxides react with HCl, what do they form?
Metal chlorides and water
What happens to the solubility of group 2 hydroxides as you go down the group?
The solubility increases
What is a sulfate ion?
SO4 2-
What happens to the solubility of group 2 sulfates as you go down the group?
The solubility decreases
What is thermal decomposition?
When a substance breaks down (decomposes) when heated.
What is the relationship between how thermally stable a compound is and how much heat is required to break it down?
The more thermally stable a compound is, the more heat is required to break it down
What are anions?
Negative ions
What happens to large negative ions when in the presence of a cation?
They can be made unstable, distorting the anion
What is the relationship between the amount of distortion and the stability of the compound?
The greater the distortion, the less stable the compound
Why do large cations cause less distortion than small cations?
Because large cations have lower charge density
Why do carbonate/nitrate compounds become more stable as you go down the group?
Because the larger the cation, the lower the charge density, so the less distortion
What is a carbonate ion?
CO3 2-
What is a nitrate ion?
NO3 2-
Are group 1 carbonates thermally stable?
Yes, you can’t decompose them with a bunsen burner