Learn: Building a Reactivity Series from Reactions with Water

Welcome!Today we'll explore how to build a reactivity series based on reactions with water. By the end of this lesson, you'll understand how to compare the reactivity of different metals using their reactions with water. Let’s get started!

What is a Reactivity Series?A reactivity series is a list of metals ordered by their reactivity. Highly reactive metals like potassium and sodium are placed at the top, while less reactive metals like gold and platinum are at the bottom. It helps us predict how metals react with substances like water or acids.

Reactions with WaterMetals react with water to produce hydrogen gas and a metal hydroxide. Highly reactive metals like potassium and sodium react vigorously, while less reactive metals may not react at all.For example, potassium reacts explosively with water, while copper shows no reaction.

Observing ReactionsTo build a reactivity series, we observe how metals react with water. For example:Potassium: Reacts explosively, producing heat and hydrogen gas.Sodium: Reacts vigorously but less explosively.Calcium: Fizzes and forms bubbles of hydrogen gas.Copper: Shows no reaction with water.

Reaction TrendsMetals at the top of the reactivity series react more violently with water because they lose electrons more easily to form positive ions. Metals lower in the series are less reactive as they hold onto their electrons more tightly.

Building the Reactivity SeriesTo create the reactivity series, we arrange metals from most reactive to least reactive based on their reactions with water. The faster and more vigorous the reaction, the higher the metal is in the series.

Review Time!Great work! You've learned how metals react with water and how to use these observations to build a reactivity series. Let’s test your understanding.