What are the characteristics of group 2 metals and their cations?
how does this apply to the rxn: KMnO4 + NaCr ?
Is a reaction going to happen?
help! thanks a lot!
Answer:
Group 2 Metals :
The elements in Group 2 (Be, Mg, Ca, Sr, Ba and Ra) are all metals, and all but Be and Mg are active metals. These elements are often called the alkaline-earth metals. The term alkaline reflects the fact that many compounds of these metals are basic or alkaline. The term earth was historically used to describe the fact that many of these compounds are insoluble in water. Most of the chemistry of the alkaline-earth metals (Group IIA) can be predicted from the behavior of the alkali metals (Group IA). Three points should be kept in mind, however.
The alkaline-earth metals tend to lose two electrons to form M 2+ ions (Be2+, Mg2+, Ca2+, and so on).
These metals are less reactive than the neighboring alkali metal. Magnesium is less active than sodium; calcium is less active than potassium; and so on.
These metals become more active as we go down the column. Magnesium is more active than beryllium; calcium is more active than magnesium; and so on.
The alkaline-earth metals react with nonmetals to give the products expected from the electron configurations of the elements.
Mg(s) + Cl2(g) ------> MgCl2(s)
3 Mg(s) + N2(g) ------->Mg3N2(s)
Ca(s) + H2(g)-------> CaH2(s)
Because they are not as active as the alkali metals, most of these elements form oxides.
2 Mg(s) + O2(g)------> 2 MgO(s)
Calcium, strontium, and barium can also form peroxides.
2Ba(s) + O2(g) ------> 2BaO(s)
The more active members of Group IIA (Ca, Sr, and Ba) react with water at room temperature. The products of these reactions are what we might expect. Calcium, for example, loses two electrons to form Ca2+ ions when it reacts with water.
Ca---------> Ca2+ + 2 e-
These electrons are picked up by the water molecules to form H2 gas and OH- ions.
2 H2O + 2 e'---------> H2 + 2 OH-
Combining the two halves of the reaction so that electrons are conserved gives the following result.
Ca(s) + 2 H2O(l) -------> Ca2+(aq) + 2 OH-(aq) + H2(g)
Although Mg does not react with water at room temperature, it will react with steam. The products of this reaction can't be aqueous Mg2+ and OH- ions because there is no liquid water around to stabilize these ions. The products of this reaction are H2 gas and magnesium oxide, MgO.
Mg(s) + H2O(g) -----------> MgO(s) + H2(g)
There can not be a reaction like KMnO4 +NaCr.
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Help with the following questions/ I'm stuck!!?
Is a reaction going to happen?
help! thanks a lot!
Answer:
Group 2 Metals :
The elements in Group 2 (Be, Mg, Ca, Sr, Ba and Ra) are all metals, and all but Be and Mg are active metals. These elements are often called the alkaline-earth metals. The term alkaline reflects the fact that many compounds of these metals are basic or alkaline. The term earth was historically used to describe the fact that many of these compounds are insoluble in water. Most of the chemistry of the alkaline-earth metals (Group IIA) can be predicted from the behavior of the alkali metals (Group IA). Three points should be kept in mind, however.
The alkaline-earth metals tend to lose two electrons to form M 2+ ions (Be2+, Mg2+, Ca2+, and so on).
These metals are less reactive than the neighboring alkali metal. Magnesium is less active than sodium; calcium is less active than potassium; and so on.
These metals become more active as we go down the column. Magnesium is more active than beryllium; calcium is more active than magnesium; and so on.
The alkaline-earth metals react with nonmetals to give the products expected from the electron configurations of the elements.
Mg(s) + Cl2(g) ------> MgCl2(s)
3 Mg(s) + N2(g) ------->Mg3N2(s)
Ca(s) + H2(g)-------> CaH2(s)
Because they are not as active as the alkali metals, most of these elements form oxides.
2 Mg(s) + O2(g)------> 2 MgO(s)
Calcium, strontium, and barium can also form peroxides.
2Ba(s) + O2(g) ------> 2BaO(s)
The more active members of Group IIA (Ca, Sr, and Ba) react with water at room temperature. The products of these reactions are what we might expect. Calcium, for example, loses two electrons to form Ca2+ ions when it reacts with water.
Ca---------> Ca2+ + 2 e-
These electrons are picked up by the water molecules to form H2 gas and OH- ions.
2 H2O + 2 e'---------> H2 + 2 OH-
Combining the two halves of the reaction so that electrons are conserved gives the following result.
Ca(s) + 2 H2O(l) -------> Ca2+(aq) + 2 OH-(aq) + H2(g)
Although Mg does not react with water at room temperature, it will react with steam. The products of this reaction can't be aqueous Mg2+ and OH- ions because there is no liquid water around to stabilize these ions. The products of this reaction are H2 gas and magnesium oxide, MgO.
Mg(s) + H2O(g) -----------> MgO(s) + H2(g)
There can not be a reaction like KMnO4 +NaCr.
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