Percobaan Logam Alkali dan Alkali tanah | Lab Kimia | UPT Laboratorium UHO

Summary

This video introduces an experiment on alkali and alkaline earth metals, highlighting their high reactivity compared to other elements in the periodic table. The procedure includes two main tests: reactivity and flame tests. In the first, potassium is tested on water using phenolphthalein to observe reactions. The second test involves burning various materials using a Bunsen burner and nichrome wire to observe flame color changes with a cobalt plate. The experiment aims to help students understand the properties of these reactive metals.

Takeaways

• 🔬 The video demonstrates an experiment involving alkali and alkaline earth metals.
• 🎯 The objective of the experiment is for students to study the properties of alkali and alkaline earth metals.
• 🧪 Equipment used includes RAB, test tubes, nichrome wire, a burner, test tube holders, and tissue.
• ⚛️ Alkali and alkaline earth metals are more reactive than other elements in the same period of the periodic table.
• 📜 Alkali and alkaline earth metals are located on the left side of the periodic table.
• ⚡ The experiment consists of two main tests: reactivity test and flame test.
• 💧 The reactivity test involves placing a small piece of potassium on tissue and floating it on water.
• 📈 After the reaction, phenolphthalein is used to test the resulting solution.
• 🔥 The flame test involves using nichrome wire to burn various substances over a Bunsen burner and observing color changes.
• 🔍 A cobalt glass filter is used to observe flame color changes, and the experiment is repeated with other substances.

Q & A

What is the purpose of the alkali and alkaline earth metal experiment?

The purpose of the experiment is for students to learn and understand the properties of alkali and alkaline earth metals.

What equipment is used in the alkali and alkaline earth metal experiment?

The equipment used includes RAB (presumably a container or apparatus), test tubes, nichrome wire, a Bunsen burner, test tube holder, and tissue paper.

Why are alkali and alkaline earth metals more reactive than other elements in the same period?

Alkali and alkaline earth metals are more reactive because they are located on the left side of the periodic table, where their electron configuration makes them more eager to lose electrons, leading to higher reactivity.

What is the first step in testing the reactivity of alkali metals?

The first step is to clamp a small piece of potassium metal, place it on a piece of tissue, and then carefully float the tissue on the surface of water in an evaporating dish.

What happens after the potassium reacts with water?

After the reaction is complete, the solution in the dish is tested with phenolphthalein solution to observe any changes in pH, which indicates the formation of a basic solution.

What is the second stage of the experiment?

The second stage is the flame test, where different materials are tested for their flame color using nichrome wire and a Bunsen burner.

How is the flame test conducted?

A small amount of material is picked up using nichrome wire, then burned in the Bunsen burner. A cobalt blue glass is used to observe the color change in the flame.

Why is cobalt glass used during the flame test?

Cobalt glass is used to filter out certain colors and help observe specific flame color changes that might be otherwise difficult to see.

What is the expected outcome of the flame test?

Different alkali and alkaline earth metals will produce characteristic flame colors, which helps in identifying them based on their emission spectra.

What is the significance of phenolphthalein in the experiment?

Phenolphthalein is used to detect the presence of a base in the solution after the alkali metal reacts with water, as it turns pink in basic conditions.