Untitled Flashcards Set

Alkali Metals

The elements in Group 1 of the Periodic Table, known for being highly reactive and having one electron in their outer shell.

Francium

A highly radioactive alkali metal, estimated to have about 20-30g present in the Earth's crust, produced during uranium-235 decay.

Reactivity Trend

Alkali metals increase in reactivity as you go down the group due to the outer electron being further from the nucleus.

Metal Hydroxide

The product formed when alkali metals react with water, with the general formula MOH.

Oxide Formation

Alkali metals react with oxygen to form oxides, with the general formula MO.

Lithium Reaction with Water

Reacts with water to form lithium hydroxide and hydrogen gas; slower than sodium's reaction.

Potassium Reaction with Water

Reacts more vigorously with water than sodium; enough heat is produced to ignite the released hydrogen.

Caesium and Rubidium Storage

Must be stored in sealed glass tubes due to their high reactivity with air.

Electronic Configuration of Sodium

2, 8, 1; indicates the presence of one valence electron in the outer shell.

Densities of Alkali Metals

Tend to increase down the group, with lithium, sodium, and potassium being less dense than water.

Alkali Metal Properties

Soft, shiny, low melting and boiling points, and must be stored away from air and water.

Tarnishing of Alkali Metals

Alkali metals tarnish quickly when exposed to air due to their reaction with oxygen.

Reaction Equation (Sodium and Water)

2Na(s) + 2H₂O(l) → 2NaOH(aq) + H₂(g); shows the reaction of sodium with water to produce sodium hydroxide.

Hydroxide Naming Convention

The hydroxide formed is named with the metal, e.g., lithium hydroxide (LiOH).

Alkaline Solution Indicator Test

Testing the solution formed by reacting alkali metals with water shows an alkaline solution indicated by turning blue with universal indicator.

Lithium vs Sodium Reaction Speed

Lithium reacts more slowly with water than sodium, which can be seen in the rate of fizzing.

Flame Color Indicator

Potassium burns with a lilac flame, sodium with a yellow flame, and lithium burns with a red flame when reacting with oxygen.

Alkali Metals and Color of Compounds

Group 1 metal ions are colorless, yielding colorless or white compounds unless combined with colored negative ions.

Melting Point Prediction of Francium

Predicted to be around 22°C based on the trend of Group 1 alkali metals.