Which one of the following is not true for anodizing process?
Clean aluminium article is the anode and oxygen gas is evolved at the cathode.
The question asks us to identify the statement that is not true for the anodizing process. Let's analyze each option to determine the incorrect statement regarding this surface finishing technique.
Anodizing is an electrochemical process that converts the metal surface into a durable, corrosion-resistant anodic oxide finish. It involves immersing the metal part (like aluminium) in an electrolyte bath and passing an electric current through it. The metal part serves as the anode (the positive electrode).
Let's evaluate each statement:
Statement: It makes aluminium corrosion resistant.
Analysis: This is a primary benefit of the anodizing process. The oxide layer formed enhances the metal's resistance to corrosion and wear. Therefore, this statement is true.
Statement: Metals like aluminium, titanium and magnesium can be anodized.
Analysis: While most common in aluminium, the anodizing process can indeed be applied to other metals like titanium and magnesium to improve their surface properties. Therefore, this statement is generally considered true.
Statement: Clean aluminium article is the anode and oxygen gas is evolved at the cathode.
Analysis: This statement contains two parts. Let's examine each:
Since one part of the statement is incorrect, the entire statement is not true.
Statement: It is used in the aircraft industry.
Analysis: The enhanced durability, corrosion resistance, and aesthetic qualities provided by anodizing make it highly valuable in the aircraft industry for components made of aluminium alloys. Therefore, this statement is true.
Based on the analysis, the statement that inaccurately describes the anodizing process is the one concerning the location of oxygen gas evolution. In anodizing, the aluminium article functions as the anode, and it is at the anode that oxygen gas is primarily evolved, while hydrogen gas is evolved at the cathode.
Therefore, the statement "Clean aluminium article is the anode and oxygen gas is evolved at the cathode" is the one that is not true for the anodizing process.
Which one of the following is the correct order of reactivity of Mg, Al, Zn and Fe with HCI?
Which one of the following isnotan example of an oxidation reaction?
Which one of the following does NOT form oxide on reaction with oxygen?
In the joining of railway tracks, iron oxide is made to react with
When copper reacts with moist carbon dioxide (CO 2) in air, it forms a green coating of which one of the following compounds?
What is the name of the process that converts sulphide ores into oxides by heating strongly in the presence of excess air ?
Calcium oxide reacts vigorously with water to produce slaked lime whose solution is used for white-washing walls. This slaked lime reacts with component (A) in air to form a thin layer of component (B) to give a shiny finish. What are the components (A) and (B) ?
Lead nitrate on heating gives
Which one of the following equations is the balanced chemical equation for the given reaction?
Fe + H2O → Fe3O4 + H2
During white - washing of walls, slaked lime reacts slowly with carbon dioxide in air to form a thin layer of calcium carbonate on the walls. Which of the following reactions represents this correctly?
Which of the following statement is/are true?
I. In physical change new substance is formed. substance is formed.
II. In chemical change no new substance is formed.
Which of the following cells involves similar chemical reactions?
The information not obtained from balanced chemical equation is
Oxygen cannot be obtained by which one of the following methods?
Which is the most reactive metal?