Topic 4 Flashcards
What is the general formula when a group 2 metal (M) reacts with water?
M + 2H20 –> M(OH)2 +H2
What is the trend in ionisation energy down group two
As you go down there is an extra electron shell so more shielding so electrons are further away from the nucleus which reduces electrostatic attraction therefore decreasing the ionisation energy
What is the general occasion when a group to metal (M) burns in oxygen
2M + O2 –> 2MO
What is the general equation when a group 2 metal (M) reacts with chlorine?
M+ Cl2 –> MCl2
General equation when a group 2 metal oxide (M) reacts with water
MO + H2O –> M(OH)2
General equation when a group 2 metal (M) hydroxides reacts with water?
M(OH)2 (s) —> M(OH)2 (l)
Reaction between group to metal oxide (M) reacts with dilute acid
MO + 2HCl –> MCl2 + H2O
General equation when a group two metal hydroxide (M) reacts with dilute acid?
M(OH)2 + 2HCl –> MCl2 + 2H2O
Why does thermal stability increase down a group?
As you go down the group the cations get bigger so there is less distortion by anions such as carbonates or nitrates this makes them more thermally stable
Which group is more thermally stable group 1 or group 2 and why?
Group 2 has a greater charge so there is greater distortion so less thermally stable therefore group one is more thermally stable
Group 1 carbonates are thermally stable but what is the exception
Lithium carbonate
Group 1 nitrates decomposes to form what
The metal nitrate and oxygen gas
Group 2 carbonates decompose to form what
The metal oxide and carbon dioxide gas
Group 2 nitrites decomposes to form what
The metal oxide, nitrogen dioxide, and oxygen
What colour is lithium in a flame test
Red
What colour is sodium in a flame test?
Orange/yellow
What colour is potassium in a flame test
Lilac
What colour is calcium in a flame test
Brick red
What colour is Rubidium in a flame test
Red
What colour is the caesium in a flame test
Blue
What colour is strontium in a flame test
Crimson
What colour is barium in a flame test
Green
What colour is magnesium in a flame test
It doesn’t produce a colour
Why does the flame tests produce different colours
Energy is absorbed from the flame as electrons move to higher energy levels. The colours of seen when the electrons fall back down to lower energy level is releasing energy in form of light
Why do you halogens gets less reactive when you go down the group
The atoms become larger so electrons are further from the nucleus, there is also shielding. This makes it harder for large atoms to attract the electron they need.
Explain the trend in melting and boiling points as you go down group 7
As you go down group 7 there is an increase in electron shells. This means there are more London forces so the melting and boiling points are higher to overcome the intermolecular forces
What ions can chlorine displace
Bromide and iodide
What is the equation when sodium hydroxide reacts with chlorine
2NaOH(Aq) + Cl2 (g) –> NaClO (Aq) + NaCl (Aq) + H2O (l)
What is the general equation when halogen (X) reacts with a hot alkali?
3X2 + 6NaOH –> NaXO3 + 5NaX + 3H2O
