Topic 4 Flashcards
What happens to the atomic radius as you go down Group 2?
Atomic radius increases down the Group.
Atoms have more shells of electrons making the atom bigger.
How do melting points change down Group 2?
Melting points decrease down the group.
Metallic bonding weakens as atomic size increases, leading to weaker electrostatic forces.
What is the trend in 1st ionisation energy down Group 2?
1st ionisation energy decreases down the group.
Outer electrons are further from the nucleus and more shielded by inner electrons.
How does reactivity of Group 2 metals change down the group?
Reactivity increases down the group.
Increased atomic radii lead to more shielding and easier removal of outer electrons.
What is the reaction of magnesium with oxygen?
2Mg + O2 → 2MgO.
Magnesium burns with a bright white flame.
What occurs when magnesium reacts with warm water?
Mg + 2 H2O → Mg(OH)2 + H2.
This reaction is slower than with steam and no flame is produced.
What is the trend in the reaction of Group 2 metals with water?
Reactivity with cold water increases down the group.
Observations include fizzing, metal dissolving, and heating of the solution.
What do Group 2 ionic oxides produce when they react with water?
They form hydroxides.
Example: MgO + H2O → Mg(OH)2.
What is the trend in solubility of Group II hydroxides?
Solubility increases down the group.
Magnesium hydroxide is considered insoluble while barium hydroxide is highly soluble.
What is the thermal decomposition of Group 2 carbonates?
Group 2 carbonates decompose to produce oxides and carbon dioxide.
Example: MgCO3 → MgO + CO2.
What is the trend in thermal stability of Group 2 carbonates?
Thermal stability increases down the group.
Larger cations have less polarising effect on carbonate ions.
What do Group 2 nitrates decompose into upon heating?
They produce oxides, oxygen, and nitrogen dioxide.
Example: 2Mg(NO3)2 → 2MgO + 4NO2 + O2.
What is the method for conducting flame tests?
Use a nichrome wire cleaned with hydrochloric acid and observe flame color after dipping in the sample.
Different metals produce different flame colors.
What is the trend in melting and boiling points of halogens down the group?
Melting and boiling points increase down the group.
Larger molecules have more electrons, leading to stronger London forces.
How does electronegativity change down the group of halogens?
Electronegativity decreases down the group.
Atomic radii increase, reducing nucleus’s ability to attract bonding electrons.
What happens in the oxidation reactions of halide ions by halogens?
A stronger oxidising agent will displace a weaker one from its compound.
Chlorine can displace bromide and iodide ions.
What is observed when chlorine reacts with potassium bromide?
Yellow solution, Cl has displaced Br.
Chlorine is a stronger oxidizing agent than bromine.
What is disproportionation in the context of chlorine reactions?
A reaction where chlorine is both oxidised and reduced simultaneously.
Example: Cl2 + H2O → HClO + HCl.
True or False: Group 2 sulphates become more soluble down the group.
False.
BaSO4 is the least soluble.
Fill in the blank: Group 2 hydroxides are _____ soluble down the group.
more
What is the result of the reaction of calcium oxide with water?
CaO + H2O → Ca(OH)2.
Produces an alkaline solution with pH 12.
What is disproportionation in chemistry?
A reaction where an element simultaneously oxidises and reduces.
What happens to chlorine in its disproportionation reaction with water?
Chlorine changes its oxidation number from 0 to -1 and 0 to +1.
What are the products of the reaction between Cl2 and H2O?
HClO and HCl.
