10.1. Similarities and trends in the properties of the Group 2 metals, magnesium to barium, and their compounds
A subsection of Chemistry, 9701, through 10. Group 2
Listing 10 of 275 questions
Group2 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(carbonate, PbCO3, and zinc carbonate, ZnCO3, decompose on heating in a similar way to calciumcarbonate, CaCO3. 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, CaMg(CO3)2, and some impurities. When 0.642 g of a sample of dolomite reacts with an excess of hydrochloricacid, 125.0 cm3 of CO2 is formed under room conditions. Calculate the percentage of CaMg(CO3)2 in the sample of dolomite. Show all your working. Assume that none of the impurities react with HCl.  % of CaMg(CO3)2 in dolomite = %  
9701_s19_qp_42
THEORY
2019
Paper 4, Variant 2
View
Group2 nitrates decompose when heated. Write an equation for the decomposition of strontiumnitrate. Describe and explain how the thermal stability of Group2 nitrates changes with increasing atomic number. The variation in the thermal stability of Group2 amides is similar to that of Group2 nitrates. Suggest whether calcium amide, Ca(NH2)2, will decompose more or less readily than bariumamide, Ba(NH2)2. Explain your answer. Ba(NH2)2 decomposes when heated to form bariumnitride, Ba3N2, and ammonia as the only products. Write an equation for this reaction. Ba(NH2)2 contains the NH2 – ion. Predict the bond angle of NH2 –. Explain your answer using the qualitative model of electron‑pair repulsion. bond angle explanation  
9701_s19_qp_43
THEORY
2019
Paper 4, Variant 3
View
A sample of barium is heated in oxygen. Describe two observations for this reaction. Write an equation for this reaction. Include state symbols. Calciumcarbonate can be converted into calciumhydroxide in a two-step process. calcium carbonate step 1 calcium oxide step 2 calcium hydroxide Describe how the two-step process is carried out to convert calcium carbonate into calciumhydroxide. Include relevant equations. Name the type of reaction occurring when calcium carbonate is converted into calciumoxide. State one common use for both calciumcarbonate and calciumhydroxide. Gallium is a silver-grey solid. Aluminium and gallium share many similar chemical properties. Construct an equation for the reaction of gallium when heated in oxygen to form galliumoxide, Ga2O3. Deduce the oxidation number of gallium in Ga2O3. Complete the table by predicting the formula of each gallium-containing product formed when galliumoxide reacts separately with hot aqueous hydrochloricacid and with hot concentrated sodiumhydroxide. reagents and conditions formula of gallium-containing product gallium oxide + hot HCl gallium oxide + hot concentrated NaOH 
9701_s20_qp_23
THEORY
2020
Paper 2, Variant 3
View
A Group2 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. State the formula and colour of the precipitate. Complete the equation to represent the reaction between MBr2 and AgNO3. MBr2 + AgNO3 →  A 0.250 g sample of pure MBr2 contains 8.415 × 10–4 mol MBr2. Calculate the relative formula mass, Mr, of MBr2. Use this to identify M. Show your working.  Mr =  M =  A sample of MBr2 is dissolved in water. Chlorine gas is then bubbled into the solution. Describe the observations for this reaction. Name the type of reaction that occurs when MBr2 reacts with chlorine gas. CompoundY is a pure insoluble solid which contains halide ions. A single reagent is added directly to compoundY to determine the halide ion present. Identify the reagent added. State the observation which would confirm that Y contains bromide ions. reagent observation  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. Complete the electron configuration of the magnesium cation present in these salts. 1s2 A sample of MgCO3is distinguished from a sample of Mg(OH)2by adding a small amount of each solid to HCl . State one similarity and one difference in these two reactions. similarity difference  
9701_s21_qp_22
THEORY
2021
Paper 2, Variant 2
View
Questions Discovered
275