FC13: Group 2 Flashcards
What is the product of a group 2 metal with oxygen?
metal oxide
What is the product of a group 2 metal with acid?
salt and hydrogen gas
What is the product of a group 2 metal with water?
metal hydroxide and hydrogen gas
Are group 2 metals soluble in water?
they are slightly soluble in water
what happens when group 2 metals dissolve in water
they release hydroxide ions and form alkaline solutions
what is the trend in alkalinity of group 2 hydroxides down the group
alkalinity increases down the group
are group 2 carbonates soluble in water and what do they dissolve in?
insoluble in water, dissolve in acid
What is formed when you react water and a group 2 oxide together
metal hydroxide
What is formed when you add excess water in the reaction with a group 2 oxide
metal ion and hydroxide ions, and so an alkaline solution is formed
what is a use of limestone (calcium carbonate)
limestone undergoes thermal decomposition to form quicklime (calcium oxide) which reacts with water to form calcium hydroxide (slaked lime), slaked lime is used to neutralise acidic soil for gardens/agriculture
what are the reactions/equations for limestone to form into slaked lime
under heat, calcium carbonate forms solid calcium oxide and carbon dioxide
calcium oxide and water forms aqueous calcium hydroxide
what is a use of magnesium hydroxide
as an antacid in indigestion remedies to neutralise excess stomach acid
what is the reaction/equation of how magnesium hydroxide (milk of magnesia) works as an antacid
magnesium hydroxide and hydrochloric acid forms magnesium chloride and water and therefore neutralising the HCl
what is a use of calcium carbonate and write the equation/reaction of how it works
can be used as an antacid
calcium carbonate + HCl forms calcium chloride and water and carbon dioxide
what is an issue in using calcium carbonate as an antacid?
the gas produced can cause bloating/discomfort
explain the trend of increasing alkalinity as you go down group 2
the hydroxides increase in solubility as you go down the group and so dissociate hydroxide ions more readily hence the increasing pH down the group
state and explain the rate at which hydrogen is produced if you use calcium instead of magnesium if you react it with HNO3, and what difference in volume of hydrogen would be produced although using same number of moles
would increase because calcium has a lower ionisation energy than magnesium
a higher volume of hydrogen would be produced because calcium reacts with water in the aqueous acid to produce extra H2
why would barium hydroxide or sodium carbonate be less suited to use as indigestion treatments compared to magnesium hydroxide or calcium carbonate
they are both very soluble compared to the others and so the liquid in the mouth/stomach would be too alkaline resulting in damage
state and explain the ionisation energy trend down group 2
decreases, because number of electron shells increases down group 2, the greater shielding effect outweighs the greater nuclear charge, and so atomic radius increases down group 2, and so the outermost electrons are further away from nucleus as you go down group 2 and so the attraction between the nucleus and the outermost electrons decreases as you go down the group and so ionisation energy decreases down group 2
