Group 2 (A Level only)：練習題

What are the gaseous products formed when anhydrous magnesium nitrate, \(\text{Mg(NO}_3)_2\), is strongly heated?

A solid mixture contains equimolar amounts of \(\text{Mg(OH)}_2\) and \(\text{Ba(OH)}_2\). Excess water is added to the mixture, which is stirred thoroughly and then filtered.

Which row correctly describes the main Group 2 compound found in the residue on the filter paper and the approximate \(\text{pH}\) of the resulting filtrate?

Which statement best explains the trend in the thermal stability of the Group 2 carbonates as the group is descended from magnesium to barium?

Which Group 2 element reacts most vigorously with cold water under standard laboratory conditions?

Which statement correctly explains why the thermal stability of Group 2 carbonates increases down the group from \(\text{MgCO}_3\) to \(\text{BaCO}_3\)?

Write a balanced chemical equation, including state symbols, for the reaction between solid barium oxide, \(\text{BaO}\), and dilute hydrochloric acid, \(\text{HCl}\).

Write the balanced equation for the thermal decomposition of anhydrous calcium nitrate, \(\text{Ca(NO}_3)_2\), and state two observations during the decomposition.

State the trend in the thermal stability of Group 2 nitrates down the group from \(\text{Mg(NO}_3)_2\) to \(\text{Ba(NO}_3)_2\).

Group 2 metals and their oxides react with dilute acids to form salts.

(a) Write a balanced equation for the reaction between solid magnesium oxide and dilute hydrochloric acid.
(b) Describe what is observed when a piece of barium metal is added to excess dilute sulfuric acid.
(c) Explain why the reaction between solid barium carbonate and dilute sulfuric acid quickly stops, whereas solid barium carbonate reacts completely with dilute hydrochloric acid.

Group 2 nitrates undergo thermal decomposition when heated strongly.

(a) Write a balanced equation for the thermal decomposition of anhydrous calcium nitrate, \(\text{Ca(NO}_3\text{)}_2\).
(b) State two observations made during the thermal decomposition of anhydrous calcium nitrate.
(c) State and explain the trend in the thermal stability of Group 2 nitrates down the group from \(\text{Mg(NO}_3\text{)}_2\) to \(\text{Ba(NO}_3\text{)}_2\) in terms of the polarising power of the cations.