Group 2 Flashcards
What are the chemical properties of group 1/2 elements
they are very reactive as they react by losing their outmost electron becoming a 1+ or 2+ ion
What are the trends for group 1/2 elements going down the group - reactivity
both of their elements get more reactive as it becomes easier to lose their outer shell electron because the outer electron is further and more shielded from the nucleus so there is less attraction
What is the difference is reactivity with group 1 and 2
group 2 elements are less reactive then the corresponding group 1 element as it takes more energy to lose 2 electron instead of 1
Reactions of group 2 - what is produced when they react with oxygen
it give the metal oxide
Reactions of group 2 - what is produced when they react with water
metal hydroxide and hydrogen
What must you do when writing equations for reactions
balance it and include state symbols
Reactions of group 2 - what can you observe when they react with water
bubbles from and the reaction gets more vigorous down the group (more bubbles!)
Group 2 - metal oxides and hydroxides are
bases, the ones that are soluble give alkaline solutions and the solutions get more alkali down the group (higher pH) and react with acids
What happens to group 2 carbonates when they are heated
they decompose and give the solid metal oxide and carbon dioxide gas and the process is known as thermal decomposition
What observations do you see when group 2 carbonate is heated
you don’t see much as mostly we start with a white solid and end with one and carbon dioxide gas is colourless so you should bubble gas through limewater and it will turn cloudy
Group 2 carbonates - what is the trend going down the group when heated
down the group they get more thermally stable which means more heat is needed to decompose them
Why do group 2 carbonates get more thermally stable down the group ( using magnesium carbonate as an example)
going down the group 2 carbonates, the cations all have the same charge (2+) but they get bigger in size (more shells) so their charge density is decreasing. Mg2+ is a small, highly charged ion with a very high charge density so it pulls strongly at the negative charge cloud of the large carbonate ion, polarising it, helping git pull apart so MgCO3 decomposes most easily
Solubility of group 2 compounds - hydroxides and carbonates
hydroxides - vary from insoluble to soluble and get more soluble down the group
carbonates - they are all insoluble but get even more insoluble down the group
Describe a simple experiment so find out the thermal stability of group 2 carbonates (included observations and how to keep it a fair test)
heat group2 carbonate and pass gas produced through limewater. Then time how long it tales for limewater to go cloudy. Observation = as you go down the group it will take longer for the limewater to go cloudy. Fair test = same moles of g2 carbonate, same surface area of g2 carbonate, same heating conditions, same volume of limewater
Trends of group 2 compounds
solubility of G2 hydroxides increases down the group
solubility of G2 carbonates decreases down the group
thermal stability of G2 carbonates increase down the group
