The table lists values of solubility products, Ksp, of some Group 2 carbonates. solubility product in water at 298K, Ksp/mol²dm⁻⁶ MgCO₃ 1.0 x 10⁻⁵ CaCO₃ 5.0 x 10⁻⁹ SrCO₃ 1.1 x 10⁻¹⁰

1. (a)Use the data in the table to describe the trend in the solubility of the Group 2 carbonates down the group.[1]
2. (b)(i)Write an equation to show the equilibrium for the solubility product for MgCO₃. Include state symbols.[1]
3. (b)(ii)With reference to your equation in (i), suggest what is observed when a few cm³ of concentrated Na₂CO₃(aq) are added to a saturated solution of MgCO₃. Explain your answer.[2]
4. (c)Use the data in the table to calculate the solubility of MgCO₃ in water at 298 K, in gdm⁻³. solubility of MgCO₃ = .............................. gdm⁻³[2]
5. (d)(i)Magnesium nitrate decomposes at a lower temperature than barium nitrate. Explain why.[2]
6. (d)(ii)A sample of barium nitrate was heated strongly until no further change occurred. A white solid was formed. Write an equation for the action of heat on barium nitrate.[1]
7. (d)(iii)When water was added to the white solid produced in (d)(ii), an alkaline solution was produced. Adding sulfuric acid to this solution produced a white precipitate. Write equations to explain these observations.[2]