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प्रश्न
When one of the metals in an alloy is mercury the alloy is called _______.
विकल्प
amalgam
sodium amalgam
zinc amalgam
all the above
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उत्तर
When one of the metals in an alloy is mercury the alloy is called amalgam.
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संबंधित प्रश्न
Write two methods of preventing the rusting of iron.
Two methods by which rusting of iron can be prevented are ______ and ______.
Explain why Iron sheets are coated with zinc during galvanization.
Choose the correct answer from the options given below:
Heating an ore in a limited supply of air or in the absence of air at a temperature just below its melting point is known as
A. Smelting
B. Ore-dressing
C. Calcination
D. Bessemerisation
What type of chemical reaction is involved in the corrosion of iron?
Fill in the following blank with suitable word:
The process of depositing a thin layer of zinc on iron articles is called .............
Fill in the following blanks with suitable words:
Tiffin boxes are electroplated with .............. but car bumpers are electroplated with ............... to protect them from rusting.
What is the corrosion of iron known as?
Explain why, the galvanised iron article is protected against rusting even if the zinc layer is broken.
If copper is kept exposed to damp air for a considerable time, it gets a green coating on its surface. This is due to the formation of:
(a) hydrated copper sulphate
(b) copper oxide
(c) basic copper carbonate
(d) copper nitrate
Four metals P, Q, R and S are all obtained by the reduction of their oxides with carbon. Metal P is used to form a thin layer over the sheets of metal S to prevent its corrosion. Metal Q is used for electroplating tiffin boxes made of metal S whereas metal R is used in making car batteries. Metals Q and R form an alloy called solder. What are metals P, Q, R and S? How have you arrived at this conclusion?
Name the metal which is a constituent of plant pigment?
Explain how the activity series accounts for each of the following:
tendency to corrosion
Compare roasting and calcination.
Explain with reason:
Roasting is carried out on sulphide ores and not on carbonate ores.
No chemical reaction takes place when granules of a solid, A, are mixed with the powder of another solid, B. However when the mixture is heated, a reaction takes place between its components. One of the products, C, is a metal and settles down in the molten state while the other product, D, floats over it. It was observed that the reaction is highly exothermic.
(i) Based on the given information make an assumption about A and B and write a chemical equation for the chemical reaction indicating the conditions of reaction, physical state of reactants and products and thermal status of reaction.
(ii) Mention any two types of reactions under which above chemical reaction can be classified.
What are the adverse effects of corrosion?
What is "rusting"? Describe with a labelled diagram an activity to investigate the conditions under which iron rusts.
Answer the following question.
List two properties of alloys.
Give a reason why rust turns moist red litmus blue.
Give reason for the following:
A suspension of rust is basic in nature.
_______ forms a green colour in the water.
Rusting of iron : Fe2O3 : : corrosion of copper : ______
Write scientific reason.
Anodization method is useful for prevention of the corrosion of the aluminium.
Write scientific reason.
Coins are made from metals and alloys.
Draw a neat labelled diagram.
Electroplating
Complete flow chart given below.
Write a molecular formula for rust.
Observe the following diagram and write answers.
- Name the method.
- Explain the method.
- Give two examples of this method.
Give the equation for the formation of rust.
Which among the following alloys contain mercury as one of its constituents?
Give an example of a chemical reaction for the following situation:
Sound is produced
