Ch 8 - Group 2 Metals (Alkaline Earth Metals)

Practice flashcards covering the reactions, physical properties, chemical trends, and thermal stability of Group 2 elements and their compounds based on lecture notes.

General equation for Group 2 metal reaction with oxygen

$2X + O_2 \rightarrow 2XO$ (where $X$ is a Group 2 metal).

Beryllium (Be) reaction with water

No reaction with water or steam due to a strong protective oxide layer.

Flame color of Calcium (Ca)

Brick-red.

Flame color of Barium (Ba)

Apple-green.

Flame color of Strontium (Sr)

Crimson red.

Magnesium (Mg) reaction with oxygen observation

Burns easily with an intense, blinding white flame.

Beryllium Oxide ($BeO$) properties

Amphoteric (reacts with both acids and bases) and unreactive towards water due to covalent characters.

Solubility trend of Group 2 Hydroxides ($X(OH)_2$)

Solubility increases down the group.

Solubility trend of Group 2 Sulfates ($XSO_4$)

Solubility decreases down the group ($BeSO_4$ and $MgSO_4$ are soluble, while $BaSO_4$ is insoluble).

General equation for thermal decomposition of Group 2 Nitrates

$$2X(NO_3)_2 \rightarrow 2XO + 4NO_2 + O_2$$

Observation of Group 2 Nitrate decomposition

Evolution of brown fumes of $NO_2$, production of oxygen gas, and a white metal oxide remains.

General equation for thermal decomposition of Group 2 Carbonates

$$XCO_3 \rightarrow XO + CO_2$$

Thermal stability trend for Group 2 Nitrates and Carbonates

Stability increases down the group, meaning higher temperatures are required for decomposition.

Atomic radius trend in Group 2

Increases down the group because more electron shells are added.

Melting and Boiling points trend in Group 2

Decreases down the group due to weaker metallic bonding.

Reactivity trend with water and acids

Increases down the group from Beryllium (very low/no reaction) to Barium (very high/rapid reaction).

Basicity trend of Group 2 Oxides and Hydroxides

Basicity increases down the group ($BeO$ is amphoteric/weakly basic, while $BaO$ and $Ba(OH)_2$ are very strongly basic).

Reaction of Barium (Ba) with dilute sulfuric acid ($H_2SO_4$)

Reaction stops almost instantly because an insoluble layer of $BaSO_4$ forms on the metal surface.

Solubility trend of Group 2 Carbonates ($XCO_3$)

Solubility decreases down the group.