Group 1 (Alkali Metals) Flashcards

All 6 cards in this deck

Why is sodium classified as an alkali metal?

It is in group 1, the first column on the left of the periodic table, so its atoms have 1 electron in the outer shell (Na is 2.8.1).

Recall two physical properties of the alkali metals.

They are soft and have relatively low melting points.

True or false? Like most other metals, alkali metals are hard and have high melting points.

False. Alkali metals are soft and have relatively low melting points (e.g. potassium melts at about 63 °C).

What would you see when a small piece of sodium is dropped onto water?

Effervescence (bubbles/fizzing), the metal melts into a ball and moves quickly on the surface, and it gets smaller and disappears.

What are the steps to write the balanced symbol equation, with state symbols, for an alkali metal reacting with water?

e.g. potassium and water

1. Products are the metal hydroxide + hydrogen: KOH and $\mathrm{H_2}$
2. Balance: $2\mathrm{K} + 2\mathrm{H_2O} \rightarrow 2\mathrm{KOH} + \mathrm{H_2}$
3. Add state symbols: $2\mathrm{K}(s) + 2\mathrm{H_2O}(l) \rightarrow 2\mathrm{KOH}(aq) + \mathrm{H_2}(g)$

What effect does the solution left after an alkali metal reacts with water have on universal indicator?

It turns universal indicator blue/purple — the metal hydroxide solution is alkaline (pH above 7).