Question
(ii) Potassium is higher in the reactivity series than calcium and reacts more vigorously with water than calcium reacts with water. State why potassium is higher in the reactivity series and reacts more vigorously with water than calcium.
Answer
4.1
(221 Votes)
Joey
Expert · Tutor for 3 years
Answer
Potassium is higher in the reactivity series and reacts more vigorously with water than calcium because it loses its single valence electron more easily than calcium loses its two valence electrons, leading to a more rapid and energetic reaction.
Explanation
## Step 1:The reactivity of metals is determined by their ability to lose electrons and form positive ions. Metals that lose electrons more easily are higher in the reactivity series.## Step 2:Potassium is in Group 1 of the Periodic Table and has one valence electron. This single electron is relatively far from the nucleus and is shielded by inner electron shells, making it easier to lose.## Step 3:Calcium is in Group 2 of the Periodic Table and has two valence electrons. These electrons are also far from the nucleus but are held more tightly than the single valence electron in potassium because of the higher nuclear charge and the need to lose two electrons to achieve a stable configuration.## Step 4:Because potassium loses its single valence electron more easily than calcium loses its two valence electrons, potassium is higher in the reactivity series.## Step 5:When potassium reacts with water, it loses its valence electron quickly, forming potassium hydroxide and hydrogen gas. This reaction releases a significant amount of energy, causing vigorous bubbling and sometimes even flames.## Step 6:Calcium also reacts with water to form calcium hydroxide and hydrogen gas, but the reaction is less vigorous because it loses its electrons less readily compared to potassium.