Group 2 Flashcards
(19 cards)
What is the trend of atomic radius
It increases as you go down the group because there are more electrons
What is the 1st ionisation energy trend
It decreases as you go down the group because more electron shells are added so the outer electron shell is getting further away from the nucleus
What is the trend of the melting and boiling point
It decreases because the delocalised electrons are further away from the nucleus
What is the trend of reactivity with water
They get more reactive going down the group
What is the type of reaction with a group 2 metal and water
It is a redox reaction
How does magnesium react with water and steam
It reacts very slowly with cold water but rapidly with steam, it forms an alkali oxide and hydrogen
How does calcium react with water and steam
Reacts in the same way as magnesium but more vigorously,
Strontium and Barium react more vigorously still
How are most metals extracted from the earth’s crust
By reacting the oxide with carbon
Why does extracting with carbon not work for titanium
It forms titanium carbide which makes the metal brittle
How is titanium oxide extracted
It is first reacted with chlorine and carbon to form titanium chloride and carbon monoxide,
Titanium chloride is then reduced to titanium by a reaction with magnesium
What is the trend of solubilities of hydroxides
Going down the group, group 2 hydroxides become more soluble,
Hydroxides are all white solids
What is the solubility of magnesium hydroxide
It is almost insoluble- it is sold as a suspension in water rather than a solution
What is the solubility of barium hydroxide
It dissolves to produce a strongly alkaline solution
What is the trend of solubilities of sulfates
They become less soluble going down group 2
How soluble is barium sulfate
It is virtually insoluble
How is barium sulfate used to test for sulfate ions in solution
It is first acidified with nitric or hydrochloric acid,
Barium chloride solution is then added to the solution under test and if a sulfate is present, a white precipitate of barium sulfate is formed,
The addition of acid removes carbonate ions as carbon dioxide,
How is Barium sulfate used in medicine
It is taken by mouth as a barium meal to outline the gut in medical x-rays (very good at absorbing them), this test is safe, even though barium compounds are highly toxic, because barium sulfate is so insoluble
How is magnesium hydroxide used in medicine
It is used in indigestion remedies to neutralise excess stomach acid which causes heartburn, indigestion and wind
How is calcium hydroxide used in agriculture
Called slaked lime and is sued to treat acidic soil, most plants have an optimum level of alkalinity in which they thrive
