Class 10 Science - Chapter Metals and Non-Metals NCERT Solutions | You must have seen tarnished copper vess
You must have seen tarnished copper vessels being cleaned with lemon or tamarind juice. Explain why these sour substances are effective in cleaning the vessels.
Copper metal reacts with atmospheric carbon dioxide and forms copper carbonate and as a result, which copper vessel loses its shiny brown surface and forms a green layer of copper carbonate. Lemon or tamarind contain acid that neutralises the base copper carbonate and dissolves the layer. So, tarnished copper vessels using lemon and tamarind, copper vessels retain their shine.
More Questions From Class 10 Science - Chapter Metals and Non-Metals
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Give an example of a metal which
(i) is a liquid at room temperature.
(ii) can be easily cut with a knife.
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(iv) is a poor conductor of heat. - Q:-
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Samples of four metals A, B, C and D were taken and added to the following solution one by one. The results obtained have been tabulated as follows.
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(b) Assess the usefulness of these tests in distinguishing between metals and non-metals. - Q:-
Food cans are coated with tin and not with zinc because
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(b) zinc has a higher melting point than tin.
(c) zinc is more reactive than tin.
(d) zinc is less reactive than tin. - Q:-
Why do ionic compounds have high melting points?
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Metallic oxides of zinc, magnesium and copper were heated with the following metals.
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A man went door to door posing as a goldsmith. He promised to bring back the glitter of old and dull gold ornaments. An unsuspecting lady gave a set of gold bangles to him which he dipped in a particular solution. The bangles sparkled like new but their weight was reduced drastically. The lady was upset but after a futile argument the man beat a hasty retreat. Can you play the detective to find out the nature of the solution he had used?
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