Tag: chemistry of non-metals
Questions Related to chemistry of non-metals
Greyish white metal which is a good conductor of electricity and heat , has a boiling point of $920^\circ C$ is :
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aluminium.
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tin.
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iron.
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zinc.
Greyish white metal which is a good conductor of electricity and heat and has a boiling point of $920^\circ C$ is zinc.
Hence, the correct option is $D$.
Zinc has a melting point of :
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$233^\circ C$
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$219^\circ C$
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$333^\circ C$
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$419^\circ C$
The metal Zinc has a melting point of $419^\circ C$.
A bar of zinc generates a characteristic sound when bent, similar to_________.
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Tin cry
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Water splashing
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Glass breaking
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None of above
A bar of zinc generates a characteristic sound when bent, similar to tin cry. A tin cry is the characteristic sound heard when a bar of tin is bent. Variously described as a "screaming" or "crackling" sound, the effect is caused by the crystal twinning in the metal.
Platinum metal can be dissolved in:
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hot conc. HCl
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hot conc. $HNO _3$
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hot dil. $H _2SO _4$
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a mixture of conc. HCl and $HNO _3$
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Traditional aqua regia is a mixture of concentrated nitric and hydrochloric acids in a ratio of 1:3 that can dissolve noble metals such as gold, platinum and palladium, even though the metals are not soluble in either acid alone.
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Hence option D is correct answer.
The most reactive metal among the following is:
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Fe
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Pt
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Ni
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Co
Arrange $Si, Be, Mg, Na$ and $P$ in the increasing order of metallic character:
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$P<Be<Si<Mg<Na$
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$P<Si<Be<Mg<Na$
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$Si<P<Mg<Na<Be$
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$Na<Mg<Be<Si<P$
metallic character increases down the group and decreases along the period as we move left to right. Hence the order of increasing metallic character is
In vapour state a metal is mono atomic.
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True
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False
There are no definitive chemical bonds between two metal atoms in a lattice. They all are held together by the so-called metallic bond. The valence electrons are not shared between metal atoms. Hence they exist as a single metal atom in their lattice unit.
Metals have:
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high melting and boiling point
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low melting and boiling point
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high melting and low boiling point
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low melting and high boiling point
1) High melting and boiling point
2) Metallic bonding is the strong attraction between closely packed positive metal ions and a 'sea' of delocalised electrons.
3) The attraction between the metal ions and the delocalised electrons must be overcome to melt or to boil a metal.
4) These attractive forces are strong, so metals have high melting and boiling points.
Sodium and potassium are soft even after being metals because of:
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strong intermolecular forces
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weak cohesive forces
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high melting point
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low boiling point
Hardness of a metal is determined by the strong cohesive forces between the atoms. The cohesive forces between atoms of these metals are very weak. The bonding in these metals is weak and electrons are not located over a single atom but over a number of atoms. The weak bonding results in softness of metal.
A metal which is lighter than water is:
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lithium
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gold
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silver
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iron