Reactions of Group 2 Compounds Flashcards
(18 cards)
Reactions of group 2 elements with water [blank] going down the group
Increases
What else can be reacted with water to form a metal hydroxide instead of just the group 2 metal?
the group 2 metal oxdide
What is the general word equation for the reaction of metal oxides + water?
metal oxide + water → metal hydroxide
What happens to the solubility of group 2 metals going down the group?
The solubility increases
What is released when group 2 metals are dissolved in water?
The metal ion and 2 hydroxide ions
What determines the alkalinity of a metal hydroxide solution?
The concentration of hydroxide ions
Will the alkalinity/pH of a solution be high or low when there is a high concentration of hydroxide ions?
High alkalinity/pH
The more [blank] a group 2 metal hydroxide is in water, the higher the concentration of [blank] ions released
fill in the blank
1) soluble
2) Hydroxide ions
Why are more hydroxide ions released in solution going down group 2?
Because the solubility of the group 2 metal hydroxides in water increases, so more hydroxide ions are released
Explain why the solutions of group 2 hydroxides become more alkaline going down group 2
- The solubility of group 2 metal hydroxides in water increases going down the group
- This increases the concentration of hydroxide ions released in the solution
- This increases the alkalinity of the group 2 hydroxides going down the group
Metal hydroxides can be used as [blank] in neutralisation reactions
fill in the blank
Bases
What can Calcium hydroxide be used for?
It can be used in agriculture to neutralise acid soils
What is the equation for the neutralisation reaction between Calcium hydroxide and acid that occurs when calcium hydroxide neutralises acid soils
Ca(OH)2 + 2H+* → Ca 2+ + H2
*H+ is there as a general acid, the Calcium salt produced is dependent on the acid used, e.g. is HCl was used then CaCl2 would be produced
What is the general word equation for neutralisation reactions?
Acid + Alkali → Salt + Water
What are Mg(OH)2 and/or CaCO3 used for?
Antacids to treat indigestion
What is the equation for the neutralisation reaction between Magnesium hydroxide and HCl that occurs when magnesium is used as an antacid for indigestion
Mg(OH)2 + 2HCl → MgCl2 + 2H2O
What is the equation for the neutralisation reaction between Calcium Carbonate and HCl that occurs when magnesium is used as an antacid for indigestion
CaCO3 + 2HCl → CaCl2 + 2H2O
Suggest a reason why CaCO3 is used as an antacid instead of calcium hydroxide (Ca(OH)2)
The alkalinity of calcium hydroxide may be harmful to body tissues
