Topic 4 Periodic table Flashcards
what do water and group 2 metal react to form
metal hydroxides
What is the reaction between magnesuim & water like
reacts very slowly + bubbles of hydrogen gas form
what can be seen in the reaction of G2 metal with water
- As you go down the group the level of bubbling, effervecence & vigour increase
what is the model reaction of G2 metals with water
M + 2H2O = M(OH)2 + H2O
what does calcuim form in the reaction with water
white precipitate
what does Sr form in the reaction with water
Colourless solution
what does Ba form in the reaction with water
Colourless solution
what do G2 metals form when they react with oxygen
metal oxides
what is the model equation of the reaction of G2 metal with oxygen
2M + O2 = 2MO
what is formed when G2 metal react with chlorine
Metal Chlorides
what is the model equation for the reaction of G2 metals with chlorine
M + Cl2 = MCl2
what is the observation in the reaction between G2 metals and chlorine
a yellow glow can be seen
what happens in the reaction between magnesuim & steam
Reacts very vigourously
what is formed with magnesuim is reacted with steam
Magnesuim Oxide
What is formed when G2 oxides react with water
Metal Hydroxides
What happens to the alkalinity of the G2 hydroxides as you go down the group
Become more alkaline as there is more OH being dissolved
what are formed when G2 oxides are reacted with acids
Salt (either sulphate or chloride)
Water
what happens when G2 hydroxides are reacted with acids
forms colourless solution of metal salts
what happens to the solubility of G2 hydroxides as you go down the group
increase
what happens to the solubility of G2 sulphates as you go down the group
decrease
what can be used as test for sulpahtes
adding HCL & baruim chloride to form baruim sulphate which is a white precipitate
what is thermal decomposition
breakdown of a compound into 2 or more different substances using heat
what is formed in the TD of G2 carbonates
Group 2 Carbonates breakdown via thermal decomposition to form metal oxides and carbon dioxide.
what happens to G2 carbonates as you go down the group and what is required
Going down the group, the carbonates become more stable, and more heat is needed to break them.
what is formed in the TD of G2 nitrates
Group 2 nitrates undergo thermal decomposition to form metal oxide, nitrogen dioxide and oxygen.
how does each of the products of the TD of G2 nitrates look like
The group 2 nitrates are white solids, the metal oxide is also a white solid. Nitrogen dioxide is a brown gas
what is one precaution that must be taken in the TD of G2 nitrates
Since nitrogen dioxide is toxic, the thermal decomposition of nitrates take place in a fume cupboard.
what happens to G2 nitrates as you go down the group and what is required
The nitrates become more stable down the group and so require more heat.
what happen during thermal stability reaction
when carbonate/nitrate ion is placed near positive G2 ion the G2 ion attracts the delocalised electrons towards itself. The carbonate/nitrate ion becomes polarized which then weakens the C-O bond. If this is heated then the CO2 breaks free and forms a metal oxide
how the reaction between carbonate ion & G2 cation change as you go down the group
- As you go down the group the size of ion increases which decreases the charge density.
- The ability to polarize the carbonate ion decreases
- The C-O bond in the carbonate ion is weakened less
what does TD of G1 nitrate form
- Metal Nitrate
- Oxygen
what happens in the TD of G1 carbonate
- Decomposition won’t take place as they require high temperaturs
which element is an exception for the pattern of the TD of G1 nitrates and what does it form
- Lithuim
- Forms Metal Nitrate, Nitrogen dioxide and oxygen
what are the 3 steps to flame test
- Clean platinuim/nichrome wire by dipping in concentrated HCL
- Dip into the sample
- Place the loop into Blue bunsen burner