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Worksheeth - Extraction of Metal

This document contains questions about the extraction of metals and corrosion. It discusses the process of extracting aluminum from its ore. Aluminum oxide is converted to pure aluminum oxide which then undergoes electrolysis. Electrolysis involves passing an electric current through molten aluminum oxide to reduce it to aluminum metal. Graphite rods act as electrodes and carbon adds to lower the electrolysis temperature. Ions form at the electrodes, with aluminum ions plating at the cathode. The anodes need frequent replacement due to corrosion. Aluminum oxide reacts with both acids and bases, forming aluminum salts.

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Sindhu Priya
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© © All Rights Reserved
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Download as DOCX, PDF, TXT or read online on Scribd
90 views

Worksheeth - Extraction of Metal

This document contains questions about the extraction of metals and corrosion. It discusses the process of extracting aluminum from its ore. Aluminum oxide is converted to pure aluminum oxide which then undergoes electrolysis. Electrolysis involves passing an electric current through molten aluminum oxide to reduce it to aluminum metal. Graphite rods act as electrodes and carbon adds to lower the electrolysis temperature. Ions form at the electrodes, with aluminum ions plating at the cathode. The anodes need frequent replacement due to corrosion. Aluminum oxide reacts with both acids and bases, forming aluminum salts.

Uploaded by

Sindhu Priya
Copyright
© © All Rights Reserved
Available Formats
Download as DOCX, PDF, TXT or read online on Scribd
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NAME : ______________________________________ CLASS : ___________________ SEC : _______

DATE OF ISSUE: _________________ DATE OF SUBMISSION : ________________

TOPIC: EXTRACTION OF METALS AND CORROSION


(1)

(b)

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(3)

Complete the following using the words below

Anode cathode electrolyte ions solution

In electroplating , you make the object to be electroplated the_____________________.

The _______________is the plating metal. The _______________is an

aqueous_____________________containing ________________ of the plating material.

(4) Aluminium is extracted from its ore. The ore is converted into pure aluminium oxide, which then
undergoes electrolysis as shown.

Page 2 of 4
(a) (i) Name an ore of

aluminium. ....................................................................................................................................... [1]

(b) (ii) What is meant by the term

electrolysis? ...........................................................................................................................................

.. ....................................................................................................................................... [2]

(c) (b) Aluminium oxide has a melting point of about 2000°C, but the electrolysis process operates at

about 900°C. (i) Name the compound added to aluminium oxide to reduce the operating

temperature. .......................................................................................................................................

[1]

(d) (ii) Suggest one benefit to the environment of reducing the operating

temperature. ...........................................................................................................................................

.. ....................................................................................................................................... [1]

(e) (iii) Write the ionic half-equation for the reaction taking place at:

(f) the negative electrode (cathode) ........................................................................................

(g) the positive electrode (anode) ............................................................................................ [4]

(h) (iv) Explain why the anodes need frequent

replacement. ..........................................................................................................................................

... ........................................................................................................................................ [2]

(i) Aluminium oxide reacts with acids and with alkalis.

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(j) (i) What term is used to describe an oxide that reacts with acids and with

alkalis? ....................................................................................................................................... [1]

(k) (ii) Aluminium oxide reacts with dilute sulfuric acid to form a salt. State the name and write the

formula of the salt formed.

name...................................................................................................................................

formula ................................................................................................................................ [2]

(l) (iii) Aluminium oxide reacts with dilute sodium hydroxide to form a salt and one other product.

Name the other

product. ....................................................................................................................................... [1]

(m) (iv) Aluminium hydroxide, Al(OH)3, decomposes when heated to form aluminium oxide and water.

Write the chemical equation for this

reaction. ....................................................................................................................................... [2]

(n) (v) Suggest the names of two other aluminium compounds that decompose when heated to form

aluminium

oxide. ............................................................................................................................................. .......

................................................................................................................................ [2]

Page 4 of 4

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