Section 2 chemistry of the elements Flashcards
in the periodic table what are the rows and columns called?
rows - periods
columns - groups
group 0 are inert what does this mean?
they dont react much
group 1 elements become more reactive as you go…………………..
down the group
What does a reaction with water and alkali metal produce?
The Metal hydroxide and hydrogen.
What alkali metal (in group 1) reacts the most?
Potassium - lilac flame sometimes explosion
Why is potassium more reactive than sodium or lithium?
It’s outer shell electrons are lost easier because they are further away from the nucleus so feel less nuclear attraction, so if can lose electrons easier, it is more reactive!
What is the name of the group 7 elements?
The halogens
As the atomic number of halogens increase the elements have a ………….
Darker colour
Higher
Melting point
The higher up group 7 the more ………….
Reactive it is
What can halogens combine with to form hydrogen halides?
Hydrogen
When hydrogen chloride dissociates what is formed?
Hydrochloric acid
What happens in a displacement reaction?
More reactive halogens displace less reactive ones
What does a halogen displacement reaction involve?
Transfer of electrons
How do you test for hydrogen?
Put lit split in test with a reaction
If hydrogen present, will make a squeaky pop
What salts will hydrochloric acid produce?
Chloride
What salts do sulfuric acid produce?
Sulfate salts
What is produced when metal and water reacts?
Metal hydroxide and hydrogen
What is the order of reactivity?
Potassium, Sodium, Lithium, Calcium, Magnesium, Aluminium, Zinc, Iron, Copper, Silver, Gold.
Remember this by using: Please Say Little Charlie’s Monkeys And Zebras In Cages Securely Guarded.
What corrodes to make rust?
Iron and steel
What are the two types of protecting rust?
Barrier - plastics, oil
Sacrificial - using a more reactive metal
What percentage of each gas is in the atmosphere?
78% - nitrogen
21% - oxygen
Nearly 1% - argon
0.04% - CO2
How can you investigate the proportion of oxygen in the atmosphere?
Using copper
Using iron or phosphorus
How can you make oxygen in a lab?
Using hydrogen peroxide - decomposition
Manganese oxide catalyst
Collection - over water or a gas a syringe
2H2O ….. 2H2O + O2
What happens when magnesium, carbon and sulfur react with oxygen?
Magnesium - bright white flame, white powder, magnesium oxide, alkaline in water
Carbon - orange flame, produces carbon dioxide, acidic in water
Sulfur - pale blue flame, produces sulfur dioxide, acidic in water
What is upward and downward delivery used for?
Upward - collect lighter than air gases
Downward - collect heavier than air gases
What does the thermal decomposition of metal carbonates produce?
Carbon dioxide
What is carbon dioxide used in?why?
Fizzy drinks - slightly soluble in water, produces carbonic acid, makes drinks fizz
Fire extinguisher - more dense than air, sinks into flame and stops oxygen
Explain how carbon dioxide can be produced?
- Metal carbonate + acid ➡️ salt + water + carbon dioxide
- Thermal decomposition:
Metal carbonate ➡️ heat ➡️ carbon dioxide + metal oxide
What do greenhouse gases do?
Act as an insulating layer
Absorb heat and re radiate
How do you do a flame test?
Clean a platinum wire loop by dipping in HCL hold in the flame
Then dip in the sample and put back in the flame