Tag: some physical properties of metals

Questions Related to some physical properties of metals

Four metals $P$, $Q$, $R$ and $S$ react with water as given below:
I. $P$ reacts with cold water
II. $Q$ reacts with hot water
III. $R$ reacts with steam
IV. Red hot $S$ reacts with steam.
Then, highly reactive metal is:

chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. $P$

  2. $Q$

  3. $R$

  4. $S$

Show answer
Correct Option: A
Explanation:

The highly reactive metal is $P$ as it reacts with cold water. This is because, the reaction with cold water requires lowest energy of activation.

Select the object from the following which can shine (have lusture) _____________

chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. glass bowl and wooden bowls

  2. towel and toys

  3. shirts and scarfs

  4. ornaments and brass utensils

Show answer
Correct Option: D
Explanation:

1) ornaments and brass utensils both are made up of metals.

2) Metals are lustrous because of the free electrons they have.

3) The free electrons can move freely in the metal causing any light incident on them to get reflected back.

4) This reflection is specular reflection rather than diffused and thus the metal surface appears shiny or lustrous.

Metallic radii of some transition elements are given below. Which of these elements will have the highest density?
Element                    $Fe$     $CO$       $Ni$     $Cu$ 
Metallic radii/pm     126     125     125    128

chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. same 

  2. $Ni$

  3. $Co$

  4. $Cu$

Show answer
Correct Option: D

Which one of the following four metals would be displaced from the solution of its salt by other three metals?

chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. Mg

  2. Ag

  3. Zn

  4. Cu

Show answer
Correct Option: B
Explanation:

Ag metal would be displaced from the solution of its salt by Mg, Zn or Cu metals.

Among the given metals, the standard reduction potential for the half reaction $\displaystyle Ag^+ + e^- \rightarrow Ag$ is maximum.

Hence, among the given metals (ions),  $\displaystyle Ag^+ $ ion has maximum strength as oxidising agent. Hence, $\displaystyle Ag^+$ ion gains an electron and other metals loses electron.

Read the following statements and answer as true or false.
The presence of carbon in pig iron makes it brittle.

chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

 Pig iron has a very high carbon content, typically 3.8–4.7%, along with silica and other constituents of dross, which makes it very brittle, and not useful directly as a material except for limited applications.

Which of the following is not correct observation based on Ellingham diagram?

chemistry metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. A metal can reduce the oxide of other metal which lies above it in Ellingham diagram

  2. $CO$ is more effective than $C$ as reducing agent below $170^{o}C$

  3. $\Delta G^{o}$ metal oxide is higher than of $CO _{2}$ hence oxidation of metal sulphides to oxides is not favourable

  4. Need for conversion of metal sulphide to metal oxide before reduction can be explained thermodynamically

Show answer
Correct Option: A
Explanation:

As moving down of bottom of diagram metals becomes more reactive oxides will be hard to reduce.A given metal can reduce the oxides of other metal which lies above it in Ellingham diagram.

Generally ornaments are usually made up of 24 karat gold.

chemistry materials: metals and non-metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. True

  2. False

Show answer
Correct Option: B
Explanation:

Ornaments and jewellry can't be made of 100 per cent pure gold or 24 Karat gold as it is very soft and delicate. Most of jewellry are made of 22 karat to 10 karat of gold.


24 carat is pure gold so it has less strength to make ornaments. To impart strength, some impurities are mixed such as copper to make the 22 carat gold which is suitable for making ornaments. Therefore, 24 carat gold is pure gold , it is weak to make ornaments.

Non-metals have many different colours.

chemistry materials: metals and non-metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Non-metals like phosphorous exist in various colors such as white, scarlet, yellow, red, violet, black. Similarly, sulfur is pale yellow, bromine is red-brown colored in liquid and vapor state.
Thus option $A$ is correct.

Non-metals are less dense and have low melting and boiling points as compared to metals.

chemistry materials: metals and non-metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

The melting point of an element is the temperature at which it converts from solid form to a liquid. In metals, there are two types of bonding that lead to higher melting points: covalent and metallic. Covalent bonds are when electron pairs are shared equally between atoms, and they pull atoms even closer together if multiple pairs of electrons are involved. Metallic bonds involve electrons that are delocalized: they float between many atoms, not just two, and positively charged nuclei are firmly bound to the surrounding "sea" of electrons. As strong bonds between atoms give elements higher melting points, it is also true that lower melting points are a result of weaker bonds or a lack of bonds between atoms. Therefore non-metals lack metallic bonding between atoms therefore have lower melting and boiling point than metals.
Also the closed and dense packing of metals in the lattice impart them high density and strength that lacks in non-metals.
Thus option A is true.

Metals are lustrous.

chemistry materials: metals and non-metals physical properties of metals and non-metals some physical properties of metals general characteristics and uses of metals

  1. True

  2. False

Show answer
Correct Option: A
Explanation:

Metals are lustrous because of the free electrons present in them. The free electrons can move freely in the metal causing any light incident on them to get reflected back. This reflection is specular reflection rather than diffused and thus the metal surface appears shiny or lustrous.
Hence, option $A$ is correct.