Group 2

A reaction scheme for a Group 2 metal, M, is shown.

Which row is correct as M descends Group 2 from Mg to Ba?

Options

River water in an agricultural area contains $\text{NH}_4^+$, $\text{CO}_3^{2-}$, $\text{HCO}_3^-$, $\text{Cl}^-$ and $\text{NO}_3^-$ ions. This water is treated by adding a calculated quantity of calcium hydroxide.

What is precipitated from the river water when calcium hydroxide is added?

Options

A   $\text{CaCl}_2$
B   $\text{CaCO}_3$
C   $\text{Ca(NO}_3)_2$
D   $\text{NH}_4\text{OH}$

Radium is an element below barium in Group 2 of the Periodic Table.

Which equation shows what happens when solid radium nitrate, $\text{Ra}(\text{NO}_3)_2$, is heated strongly?

Options

A   $2\text{Ra}(\text{NO}_3)_2(\text{s}) \rightarrow 2\text{RaO}(\text{s}) + 4\text{NO}_2(\text{g}) + \text{O}_2(\text{g})$
B   $2\text{Ra}(\text{NO}_3)_2(\text{s}) \rightarrow 2\text{RaO}(\text{s}) + 2\text{N}_2(\text{g}) + 5\text{O}_2(\text{g})$
C   $\text{Ra}(\text{NO}_3)_2(\text{s}) \rightarrow \text{RaO}(\text{s}) + \text{N}_2\text{O}(\text{g}) + 2\text{O}_2(\text{g})$
D   $4\text{Ra}(\text{NO}_3)_2(\text{s}) \rightarrow 2\text{Ra}_2\text{O}(\text{s}) + 8\text{NO}_2(\text{g}) + 3\text{O}_2(\text{g})$

Which statement about strontium and its compounds is correct?

Options

A   Strontium hydroxide is more soluble than barium hydroxide.
B   Strontium sulfate is more soluble than magnesium sulfate.
C   Strontium nitrate has a lower thermal stability than calcium nitrate.
D   Strontium is a stronger reducing agent than magnesium.

$1.0\text{ g}$ of each of four different compounds of Group 2 elements are thermally decomposed. The residue in each decomposition is the oxide of the Group 2 element.

The volume of gas produced from each reaction is measured at room conditions.

Which substance produces the greatest volume of gas?

Options

A   calcium carbonate
B   calcium nitrate
C   strontium carbonate
D   strontium nitrate

Which statement is correct?

Options

A   Barium oxide reacts with water at room temperature to form barium hydroxide and hydrogen.
B   Calcium oxide does not react with water at room temperature.
C   Magnesium hydroxide reacts with steam to form magnesium oxide and hydrogen.
D   Strontium oxide reacts with water at room temperature to form strontium hydroxide only.

W, X, Y and Z are Group 2 elements barium, calcium, magnesium and strontium but not in that order.

• W reacts faster with dilute hydrochloric acid than Y.
• The hydroxide of X is less soluble in water than the hydroxide of W.
• The sulfate of Y is the most soluble of the sulfates of W, X, Y and Z.
• The carbonate of Z decomposes more slowly than the carbonate of W at the same temperature.

What is the $M_r$ of the nitrate of W?

Options

A   148.3
B   164.1
C   211.6
D   261.3

Substance J reacts with water. A gas is given off and the pH of the solution increases. The solution is then reacted with sulfuric acid and a white precipitate forms.

What could be substance J?

Options

A   barium
B   barium oxide
C   magnesium
D   magnesium oxide

The flow diagram shows two successive reactions starting from element Q. Element Q is either calcium or barium.

Element Q forms a nitrate that is less thermally stable than strontium nitrate.

What is the identity of compound R?

Options

A   CaO
B   Ca(OH)₂
C   BaO
D   Ba(OH)₂

The trends seen in Group 2 can be used to predict the properties of radium and its compounds.

Which statement is correct?

Options

A   Radium has the highest second ionisation energy of the elements in Group 2.
B   Radium hydroxide is the least soluble of the hydroxides of the elements in Group 2.
C   Radium carbonate has the lowest thermal stability of the carbonates of the elements in Group 2.
D   Radium reacts faster with water than the other elements in Group 2.