Pembuatan dan Rekasi Logam Alkali Tanah | Kimia SMA | Tetty Afianti

Summary

In this educational video, the instructor provides an in-depth lesson on the extraction and reactions of alkali earth metals, such as beryllium, magnesium, calcium, strontium, barium, and radium. The video covers two main extraction methods—reduction and electrolysis—explaining how each metal is isolated from its ores. Additionally, the lesson explores various reactions of alkali earth metals with halogens, oxygen, water, nitrogen, and hydrochloric acid, highlighting their distinct reactivity. The video concludes with practice questions to reinforce the learning, offering a comprehensive overview of these essential chemistry concepts.

Takeaways

• 😀 The alkali earth metals can be extracted through two main methods: reduction and electrolysis.
• 😀 Beryllium (Be) is extracted by heating BeF₂ with Na₂S and reacting it with magnesium, or through electrolysis of molten BeCl₂ with NaCl.
• 😀 Magnesium (Mg) can be extracted via the reduction of dolomite and electrolysis of seawater or MgCl₂.
• 😀 Calcium (Ca) is extracted through reduction using aluminum or sodium, or via electrolysis of CaCO₃ with HCl.
• 😀 Strontium (Sr) is extracted by heating Sr compounds to produce SrCl₂, which is then electrolyzed.
• 😀 Barium (Ba) is extracted by reducing BaO with sodium or via electrolysis of BaCl₂.
• 😀 Radium (Ra), a radioactive metal, is extracted by electrolysis of radium chloride, forming an amalgam with mercury.
• 😀 Alkali earth metals react with halogens to form halides, like calcium reacting with chlorine to form CaCl₂.
• 😀 These metals react with oxygen to form oxides (e.g., magnesium forms MgO when reacting with oxygen).
• 😀 When alkali earth metals react with water, they form hydroxides and release hydrogen gas, with calcium forming Ca(OH)₂.
• 😀 Alkali earth metals react with nitrogen at high temperatures to form nitrides, such as magnesium forming Mg₃N₂.
• 😀 The reaction of alkali earth metals with hydrochloric acid forms chloride salts and hydrogen gas, with reactions becoming faster down the group.

Q & A

What are the two main methods for extracting alkaline earth metals from their ores?

The two main methods for extracting alkaline earth metals are reduction and electrolysis.

How is beryllium (Be) extracted using the reduction method?

Beryllium is extracted by heating beryllium chloride (BeCl2) with sodium sulfide (Na2S) to form a molten mixture, which reacts with magnesium to produce beryllium metal.

Why is sodium chloride (NaCl) added to beryllium chloride (BeCl2) in the electrolysis method?

Sodium chloride is added to beryllium chloride to improve its electrical conductivity, as BeCl2 alone does not conduct electricity well enough for electrolysis.

What is the role of electrolysis in magnesium extraction?

In magnesium extraction, electrolysis of molten magnesium chloride (MgCl2) produces magnesium metal at the cathode and chlorine gas at the anode.

How is calcium (Ca) extracted using the reduction method?

Calcium can be extracted by reducing calcium oxide (CaO) with aluminum or by using sodium to reduce calcium chloride (CaCl2).

What is the main mineral used in the extraction of strontium (Sr)?

The main mineral used in the extraction of strontium is strontium sulfate (SrSO4), which is converted into strontium chloride (SrCl2) for electrolysis.

How does the reactivity of alkaline earth metals change when reacting with water?

The reactivity of alkaline earth metals with water increases from beryllium, which does not react, to barium, which reacts very quickly. Magnesium reacts more slowly.

What happens when magnesium reacts with nitrogen gas (N2)?

When magnesium reacts with nitrogen gas at high temperatures, it forms magnesium nitride (Mg3N2).

Which method is used for extracting radium (Ra), and why is it special?

Radium is extracted by electrolysis of radium chloride (RaCl2). It is special because radium is radioactive, and its extraction process involves handling radioactive materials carefully.

What is the general outcome when alkaline earth metals react with halogens?

When alkaline earth metals react with halogens, they form ionic salts. For example, calcium reacts with chlorine gas (Cl2) to form calcium chloride (CaCl2).