Group 2

Write an equation for the thermal decomposition of $\text{CaCO}_3$.

State which of $\text{CaCO}_3$ and $\text{BaCO}_3$ decomposes at a lower temperature.

Explain your answer.

The compound that decomposes at a lower temperature is ...................................................

explanation ...............................................................................................................................

Identify A.

Explain why A is less soluble than B.

Write an equation for the thermal decomposition of $\text{CaCO}_3$.

State which of $\text{CaCO}_3$ and $\text{BaCO}_3$ decomposes at a lower temperature.

Explain your answer.

The compound that decomposes at a lower temperature is ...................................................

explanation ...............................................................................................................................

Identify A.

Explain why A is less soluble than B.

Write an equation for the thermal decomposition of $\text{Mg(NO}_3)_2$.

State which of $\text{Mg(NO}_3)_2$ or $\text{Sr(NO}_3)_2$ decomposes at a lower temperature.

Explain your answer.

compound that decomposes at a lower temperature ...............................................................

explanation ...............................................................................................................................

Identify the products formed when $\text{MgO}$ reacts with dilute sulfuric acid.

Explain why A is more soluble than B.

Describe and explain the trend in the solubility of the Group 2 hydroxides down the group.

Group 2 hydroxides decompose on heating to give the corresponding metal oxide and water vapour.

Suggest which of $\text{Mg(OH)}_2$ and $\text{Sr(OH)}_2$ will decompose at a lower temperature.

Explain your answer.

Describe and explain the trend in the solubility of the Group 2 hydroxides down the group.

Group 2 hydroxides decompose on heating to give the corresponding metal oxide and water vapour.

Suggest which of $\text{Mg}(\text{OH})_2$ and $\text{Sr}(\text{OH})_2$ will decompose at a lower temperature.

Explain your answer.

Group 2 nitrates decompose when heated.

Write an equation for the decomposition of strontium nitrate.

Describe and explain how the thermal stability of Group 2 nitrates changes with increasing atomic number.

Suggest whether calcium amide, $\text{Ca}(\text{NH}_2)_2$, will decompose more or less readily than barium amide, $\text{Ba}(\text{NH}_2)_2$. Explain your answer.

$\text{Ba}(\text{NH}_2)_2$ decomposes when heated to form barium nitride, $\text{Ba}_3\text{N}_2$, and ammonia as the only products.

Write an equation for this reaction.

$\text{Ba}(\text{NH}_2)_2$ contains the $\text{NH}_2^-$ ion.

Predict the bond angle of $\text{NH}_2^-$. Explain your answer using the qualitative model of electron-pair repulsion.

bond angle:

explanation:

Group 2 carbonates decompose when heated.

Write an equation for the decomposition of the carbonate ion.

Describe and explain how the thermal stability of the Group 2 carbonates changes with increasing atomic number.

Lead(II) carbonate, $\text{PbCO}_3$, and zinc carbonate, $\text{ZnCO}_3$, decompose on heating in a similar way to calcium carbonate, $\text{CaCO}_3$.

State relevant data from the Data Booklet and use it to predict the order of thermal stability of these three carbonates.

data ............................................................................................................................................

....................................................................................................................................................

(most stable) ............................... > ............................... > .............................. (least stable)

Dolomite contains the double carbonate of calcium and magnesium, $\text{CaMg(CO}_3)_2$, and some impurities. When 0.642 g of a sample of dolomite reacts with an excess of hydrochloric acid, $125.0 \text{ cm}^3$ of $\text{CO}_2$ is formed under room conditions.

Calculate the percentage of $\text{CaMg(CO}_3)_2$ in the sample of dolomite. Show all your working.

Assume that none of the impurities react with $\text{HCl}$.

Write an equation for the change representing the first ionisation energy of magnesium. Include state symbols.

Write an equation for the reaction of strontium with cold water. Include state symbols.

Describe and explain the trend in reactivity observed in the reactions of these Group 2 metals with cold water.

Describe fully what is seen when anhydrous calcium nitrate is heated in a test-tube and decomposition occurs.

Write an equation for the decomposition of calcium nitrate.

Describe and explain the variation in thermal stability of the Group 2 metal nitrates down the group.

Describe and explain the variation in the solubility of the Group 2 metal sulfates down the group.

Describe fully what would be seen when magnesium and strontium are heated separately in oxygen.

magnesium

strontium

Write an equation for each of the following processes. Include state symbols.

calcium is burned in air

calcium carbonate is heated strongly

Calcium hydroxide is formed when water is added to calcium oxide. Calcium hydroxide and calcium carbonate are both used in agriculture.

Describe the main benefit of adding calcium hydroxide or calcium carbonate to soil.

Explain why the Group 2 hydroxides become more soluble down the group.

Describe the observations, if any, that you would make when:

● a few drops of $\text{NaOH}(\text{aq})$ are added to $\text{BaCl}_2(\text{aq})$

● a few drops of $\text{H}_2\text{SO}_4(\text{aq})$ are added to $\text{BaCl}_2(\text{aq})$.

Describe and explain how the thermal stability of the Group 2 carbonates varies down the group.

Write an equation for the change representing the first ionisation energy of magnesium. Include state symbols.

Write an equation for the reaction of strontium with cold water. Include state symbols.

Describe and explain the trend in reactivity observed in the reactions of these Group 2 metals with cold water.

Describe fully what is seen when anhydrous calcium nitrate is heated in a test-tube and decomposition occurs.

Write an equation for the decomposition of calcium nitrate.

Describe and explain the variation in thermal stability of the Group 2 metal nitrates down the group.

Describe and explain the variation in the solubility of the Group 2 metal sulfates down the group.