EduNinjaThe oxide of silicon reacts with calcium oxide in an addition reaction to produce calcium silicate, CaSiO3. The oxidation number of calcium in CaSiO3 is +II .
Calcium oxide can be made from calcium carbonate in a single-step reaction.
Identify the type of reaction that occurs.
Calcium, magnesium and radium are Group 2 elements. Radium follows the same trends as the other members of Group 2.
Write the equation for the thermal decomposition of calcium nitrate.
Suggest which of the Group 2 nitrates, calcium, magnesium or radium, requires the highest temperature to decompose. Explain your answer.
Predict what you would observe when aqueous radium chloride is added to aqueous sodium sulfate.
Do not refer to temperature changes in your answer.
Magnesium, Mg , burns in oxygen, O2.
The activation energy, Ea, for this reaction is +148 kJ mol−1.
State one observation when magnesium burns in oxygen.
Do not refer to temperature changes in your answer.
Ethanedioic acid, HO2CCO2H, has a relative molecular mass of 90.0.
Solid ethanedioic acid reacts with aqueous calcium ions to make a precipitate of calcium ethanedioate, CaC2O4.
CaC2O4 breaks down when heated to form calcium oxide, carbon dioxide and carbon monoxide.
Construct an equation to represent the reaction of CaC2O4 when heated. Include state symbols.
Identify the type of reaction which occurs when CaC2O4 is heated.
Identify another compound containing calcium ions which will also produce carbon dioxide and calcium oxide when it is heated.
Group 2 metals form alkaline solutions in water.
Write the equation for the reaction of calcium oxide with water.
Oxygen reacts readily with some metals, but each Group 2 metal requires strong heating to start the reaction with oxygen.
Suggest why strong heating is required to start these reactions.
Group 2 elements share common chemical properties.
Calcium reacts in cold water more quickly than magnesium because more energy is required to remove the outer electrons in magnesium. This occurs even though calcium atoms have a greater nuclear charge.
Explain why more energy is required to remove the outer electrons in magnesium than in calcium.
0.001 mol of strontium reacts with an excess of cold water. When the reaction is complete a colourless solution is seen.
Construct the equation for the reaction of strontium with cold water. Include state symbols.
0.005 mol of calcium and 0.005 mol of strontium are added separately to two beakers. Each beaker contains 100 cm3 of cold water.
At the end of each reaction a white solid and a colourless solution are seen in both beakers.
Predict which element, calcium or strontium, produces the more alkaline solution. Explain your answer.
Describe one observation when magnesium carbonate is added to excess dilute sulfuric acid.
Element X is a metal. X reacts with oxygen to form a black solid oxide. The oxidation state of X in this oxide is +2 . The carbonate of X,XCO3, is a green solid. It decomposes on heating to form the oxide and a colourless gas.
From the information given, state two similarities and one difference that metal X and its compounds have with Group 2 metals and their compounds.
similarity 1
similarity 2
difference 1
Write the formula of the oxide of X.
Write an equation for the reaction of XCO3 when it is heated.
Sodium and magnesium are the first two elements in the third period.
Sodium and magnesium both react with cold water to produce the same type of product in solution. With sodium the solution is clear but with magnesium it appears cloudy.
Suggest why the solution is cloudy after the reaction of magnesium with cold water.
Group 2 elements, including magnesium, react with oxygen and with dilute acids. There are trends in both the physical and chemical properties of the elements and their compounds down the group. Reactivity generally increases from Mg to Ba .
Explain why there is a general increase in reactivity from Mg to Ba .
Write an equation for the reaction of magnesium with sulfuric acid.
Oxides are compounds which usually contain oxygen combined with one other element.
Oxides are classified as follows.
acidic alkaline amphoteric basic
Sodium reacts with water.
Describe, as fully as you can, what you would see when a piece of sodium is reacted with water.
Write an equation for the reaction of sodium with water.
A Group 2 metal combines with bromine to form a crystalline solid, MBr2.
Excess aqueous AgNO3 is added to a solution of MBr2 and a precipitate forms. The mixture is filtered. The precipitate is dried and the mass of the precipitate is recorded.
Separate 1.0 g samples of three different magnesium salts are tested in order to identify the anion present in each sample.
Explain how the action of heat is used to identify which sample is:
- MgCO3
- Mg(NO3)2
- MgO .
A sample of MgCO3( s) is distinguished from a sample of Mg(OH)2( s) by adding a small amount of each solid to HCl(aq).
State one similarity and one difference in these two reactions.
similarity
difference
Describe the trend in the solubility of the sulfates of magnesium, calcium and strontium.
Explain your answer. > >
most soluble
least soluble
Group 2 carbonates decompose when heated to form the metal oxide and carbon dioxide.
Describe the variation in the thermal stability of Group 2 carbonates. Explain your answer.