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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?
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Bronze is an alloy of ______.
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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.
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Answer the following question.
List two properties of alloys.
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Galvanisation is a method of protecting iron from rusting by coating it with a thin layer of ____________.
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Amalgam is an alloy of ____________.
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Copper objects lose their shine and form green coating of ____________.
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Which among the following alloys contain mercury as one of its constituents?
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The diagram shows the reaction between metal and dil. acid.
What is the reason for different behaviour of Mg in test tube B?
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The table shown below gives information about four substances: A, B, C and D.
| SUBSTANCE | MELTING POINT (K) | ELECTRICAL CONDUCTIVITY | |
| SOLID | LIQUID/ AQUEOUS | ||
| A | 295 | Good | Good |
| B | 1210 | Poor | Good |
| C | 1890 | Poor | Good |
| D | 1160 | Poor | Poor |
Identify Ionic compounds from the above given substances.
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Marble’s popularity began in ancient Rome and Greece, where white and off-white marble were used to construct a variety of structures, from hand-held sculptures to massive pillars and buildings.
The substance not likely to contain CaCO3 is:
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Identify the correct statement from the following:
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Alloys are homogeneous mixtures of a metal with a metal or non-metal. Which among the following alloys contain non-metal as one of its constituents?
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Generally, when metals are treated with mineral acids, hydrogen gas is liberated but when metals (except Mn and Mg), treated with HNO3, hydrogen is not liberated, why?
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Write the full form of the following as it occur in biology :
AIDS
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Which of the following diseases is not sexually transmitted?
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AIDS is a sexually transmitted disease caused due to an infection by a ______
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What are the benefits of using mechanical barriers during sexual act?
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Describe sexually transmitted diseases and mention the ways to prevent them.
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