Table of Contents
- 1 Why some metals Cannot be extracted by electrolytic reduction?
- 2 Why electrolysis of aqueous metal solutions is not feasible in case of highly reactive metals?
- 3 Why oxides of highly reactive metals Cannot be reduced?
- 4 Which metals are reduced by electrolytic reduction?
- 5 Why can electrolysis not be performed on covalent substances?
- 6 How moderate reactive metals can be extracted from their ores?
- 7 How are highly reactive metals extracted by electrolytic reduction?
- 8 What is electrolytic refining?
Why some metals Cannot be extracted by electrolytic reduction?
Metals of high reactivity, such as sodium, calcium, magnesium, aluminium, etc. are extracted from their ores by electrolytic reduction. These metals cannot be reduced using carbon because carbon is less reactive than them. Metal (being positively charged) is deposited over cathode.
Which metal is not extracted by electrolytic reduction?
Reactivity and extraction method
| Metal | Method |
|---|---|
| Aluminium | Electrolysis |
| (Carbon) | (Non-metal) |
| Zinc | Reduction by carbon or carbon monoxide |
| Iron | Reduction by carbon or carbon monoxide |
Why electrolysis of aqueous metal solutions is not feasible in case of highly reactive metals?
Explanation: Highly reactive metals with lower reduction potentials than hydrogen are not obtained by electrolysis of aqueous solutions of their salts since their cations cannot be reduced at cathode in presence of water. …
Why are highly reactive metals extracted by electrolysis?
Very reactive metals, such as aluminium, form stable oxides and other compounds. Electrolysis is commonly used to extract these metals and requires a lot of electric current (energy) to reduce them to extract the metal. Less reactive metals, such as iron, form less stable oxides and other compounds.
Why oxides of highly reactive metals Cannot be reduced?
The oxides of very reactive metals cannot be reduced with carbon. This is because these metals have more affinity (more attraction) for oxygen than carbon. so carbon is unable to remove oxygen from these metal oxides and hence cannot convert them into free metals.
How the moderately reactive metal is extracted from its ore?
The moderately reactive metals are extracted by the reduction of their oxides with carbon, aluminium, sodium or calcium. Example: When zinc sulphide (zinc blende ore) is strongly heated in air (roasted), it forms zinc oxide and sulphur dioxide. This process is called roasting. This process is termed as reduction.
Which metals are reduced by electrolytic reduction?
The electrolytic reduction is a type of electrolysis. The oxides, hydroxide and chlorides of metals in fused state are electrically reduced by using this method. The metals are extracted at the cathode. Some metals like Na, K, Mg, Ca, are obtained by this process.
How is electrolytic reduction used in the extraction of metals?
In this reaction, carbon gets oxidised to carbon dioxide while the metal oxide gets reduced to its respective metal. Such metals include Zinc, Iron, lead, tin and Copper. So, highly reactive metals such as alkali metals, alkaline earth metals and aluminium are extracted using electrolytic reduction.
Why can electrolysis not be performed on covalent substances?
Ionic substances contain charged particles called ions . Electricity is the flow of electrons or ions. For electrolysis to work, the compound must contain ions. Covalent compounds cannot act as electrolytes because they contain neutral atoms .
What is the problem with carrying out electrolysis of aqueous compounds?
Electrolysing aqueous solutions of ionic compounds can be more complicated than electrolysing molten compounds, because the water molecules can provide hydrogen ions (H +) and hydroxide ions (OH -), in addition to the ions from the ionic compounds.
How moderate reactive metals can be extracted from their ores?
The moderately reactive metals are extracted by the reduction of their oxides with carbon, aluminium, sodium or calcium. Example: When zinc sulphide (zinc blende ore) is strongly heated in air (roasted), it forms zinc oxide and sulphur dioxide. This process is called roasting.
What is electrolytic reduction?
The electrolytic reduction is a type of electrolysis in which electric current is pass through an ionic substance (molten or dissolved ) producing chemical reaction at the electrodes and a decomposition of the materials. Example: Sodium metal is obtained by the electrolysis of molten Sodium Chloride.
How are highly reactive metals extracted by electrolytic reduction?
Such highly reactive metals are extracted by the electrolytic reduction of their molten chlorides or oxides. Electrolytic reduction: When metals are extracted from their molten chlorides or oxides by passing an electric current through them. This process of electrolytic reduction is also called electrolysis.
How do electrodes become active in an electrolytic reaction?
The electrodes become active when the metal used in one or either of them and the cation in the electrolyte belong to the same element. The electrodes now enter into the electrolytic reaction. At anode, the metal undergoes oxidation and dissolves in the electrolyte, while the metal is deposited on cathode due to reduction of metal ions.
What is electrolytic refining?
Electrolytic Refining: Many metals, such as copper, zinc,tin, nickel, silver, gold, etc., are refined electrolytically. In This process, the impure metal is made the anode and a thin strip of pure metal is made the cathode. A solution of the metal salt is used as an electrolyte.
How do you reduce oxides of moderately reactive metals?
Some oxides of moderately reactive metals are reduced by using aluminium as the reducing agent. In this process of reduction, the metal oxides are displaced with aluminium, and the metal is extracted. This process is called aluminothermy. A more reactive metal can displace less reactive metal from its metal oxide to give the metal.