Similarities & Trends in the Properties of the Group 2 Metals, Magnesium to Barium, & Their Compounds (Cambridge (CIE) A Level Chemistry): Exam Questions

In a firework, magnesium is the fuel and barium nitrate is the oxidising agent.

Which substances are the solid products of this reaction?

Group 2 nitrates undergo thermal decomposition according to the following equation.

X(NO₃)₂ XO + 2NO₂ + O₂

Which Group 2 nitrate requires the highest temperature to bring about its thermal decomposition?

The diagram shows some applications of compounds of Group 2 elements.

Which numbered links are correct?

Which mass of solid residue will be obtained from the thermal decomposition of 5.10 g of anhydrous calcium nitrate?

Thermal decomposition of magnesium nitrate, Mg(NO₃)₂, produces a white solid and a mixture of gases. One of the gases released is oxygen.

32.3 g of anhydrous magnesium nitrate is heated until no further reaction takes place.

What is the mass of oxygen produced?

In agriculture, lime is added to damp soil followed by the nitrogenous fertiliser ammonium sulfate. The lime reacts with ammonium sulfate in the damp soil.

Which substances are formed in this reaction?

As you go down Group 2, what are the trends in the properties in the table below?

When quicklime, water and sand are mixed, it makes lime mortar. Lime mortar hardens over time. Aqueous hydrochloric acid reacts with fresh and old lime mortar, but only the old lime mortar effervesces during the reaction. 

Which equation describes the change from fresh to old lime mortar?

A compound was thermally decomposed to a constant mass; this gave off a colourless gas that reacted with limewater. The limewater went cloudy. The solid that was left was allowed to cool, and aqueous hydrochloric acid added, a vigorous effervescence was seen.

What was the mineral compound?

Thermal decomposition of compound S releases carbon dioxide gas and forms a white solid, T. S and T are not soluble in water. Compound T is used as a refractory kiln lining.

What is compound S?

The elements in Group 2, from magnesium to barium, show specific trends in the solubility of their hydroxides and sulfates.

Which row correctly describes the variation in the solubility of these compounds as the group is descended?

Compound Q is used as a refractory lining material in kilns.

Compound R is used as a building material. It can be heated in a kiln to form compound S. When S is hydrated it forms compound T, which is used in agriculture to treat soils.

Which row correctly identifies compounds Q and S?

An anhydrous nitrate of a Group 2 metal was thermally decomposed. 6.00 g was used, and 3.06 g of gas was produced.

What is the nitrate compound?

A mixture of two Group 2 compounds, Y, were thermally decomposed.

This reaction produced a white solid and only two gaseous products. One of the gaseous products relights a glowing splint.

What could be the components of mixture Y?

Thermal decomposition of anhydrous magnesium nitrate, Mg(NO₃)₂, gives a white solid and a mixture of two gases R and S.

S is oxygen.

What is the ratio ?

When equal volumes of saturated solutions of barium hydroxide and calcium hydroxide are mixed, a white precipitate, Y, forms. The mixture is filtered, and carbon dioxide is bubbled through the filtrate, producing a second white precipitate, Z.

What are Y and Z?

A colourless solution was formed when metal Y was reacted with water. This solution then gave a white precipitate when mixed with aqueous sulfuric acid.

What is metal Y?

A student performs several experiments on element Y, an alkaline earth metal to determine its identity and the following observations are made:

1. When added to water, Y-hydroxide dissolves in water.

2. When added to water, Y-sulfate produces a white precipitate.

3. In order to thermally decompose Y-nitrate, more heat is required than to thermally decompose strontium nitrate.

4. When burned in oxygen Y will readily become YO.

What is the identity of element Y?

Group 2 metal carbonates can be used as fire retardants as they thermally decompose producing CO₂. The CO₂ removes the oxygen from the fire. Three minerals, each containing a mixture of two Group 2 metal carbonates, could be used as fire retardants.

Barytocalcite BaCa(CO₃)₂

Dolomite CaMg(CO₃)₂

Huntite Mg₃Ca(CO₃)₄

What is the order of effectiveness as a fire retardant, from best to worst?

Thermal decomposition of the nitrates of beryllium, calcium, magnesium, and strontium produces the same products. When 4.00 g of one of these anhydrous nitrates is decomposed, 2.64 g of gas is produced.

What is the nitrate?

In which row of the table are all statements comparing magnesium and barium correct?