Tag: chemistry

Questions Related to chemistry

You have three solids. One is a metal; one is an ionic compound; one is a molecular/covalent compound. You test all three solid samples to identify their bonding.

Sample Appearance Melting Point $(^{\circ}C)$ Conductivity
A Shiny $962$ conductive
B Crystalline $801$ conductive in aqueous solution
C Powdery $186$ not conductive

Based on this data, identify the type bonds present in each sample.

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Sample A is a metal.

    Sample B is a salt.

    Sample C is a molecule.

  2. Sample A is a molecule.

    Sample B is a metal.

    Sample C is a salt.

  3. Sample A is a salt.

    Sample B is a metal.

    Sample C is a molecule.

  4. Sample A is a molecule.

    Sample B is a salt.

    Sample C is a metal.

Show answer
Correct Option: A
Explanation:

Ans : (A) Sample $A$ is metal

(B) Sample $B$ is a salt
(C) Sample $C$ is a molecule
Note : - (1) We know that metal possers shiny properties and it is a good conductor of electricity.
(2) Ionic salt is dissolved in water make an electrically conductive solution. Ionic compound is formed from strong electrostatic interaction between ions which result in a higher melting point.
(3) Molecule do not have free $e^{\ominus}$ to conduct the Electricity.

Molten silver absorbs _________ which is given off on cooling causing violent spurting. This is called splitting of silver and can be prevented by covering the molten metal with a layer of charcoal.

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. carbon monooxide

  2. carbon dioxide

  3. carbon

  4. charcoal

Show answer
Correct Option: B
Explanation:

Molten silver absorbs oxygen which is given off on cooling causing violent spurting. This is called splitting of silver and can be prevented by covering the molten metal with a layer of charcoal.

The percent of silver in silver - copper alloy used for jewellery purposes has _______ % silver.

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. 20

  2. 40

  3. 60

  4. 80

Show answer
Correct Option: D
Explanation:

The percent of silver in silver - copper alloy used for jewellery purposes has 80 % silver and 20% copper. Silver copper alloy is used in coins, ornaments, silver ware, decoration pieces, etc.

Which of the following is/are true regarding the physical properties of silver?

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. It is white, lustrous, lightweight metal.

  2. It is very malleable and ductile, coming before gold in this property.

  3. It is poor conductor of heat and electricity.

  4. None of the above.

Show answer
Correct Option: D
Explanation:

The following  are true regarding the physical properties of silver.
It is white, lustrous, heavy metal.
It is very malleable and ductile, coming next to gold in this property.
It is best conductor of heat and electricity.

An element is sonorous and highly ductile. Under which category would you classify this element? What other characteristics do you expect the element to possess?

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Metal

  2. Non-Metal

  3. Metalloid

  4. Semi-conductor

Show answer
Correct Option: A
Explanation:

Metal

Malleable high melting and boiling point, lustrous hard, high density and a good conductor of heat and electricity.

Which of the following is/are true regarding uses of silver?

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Silver leaves are used in filling teeth.

  2. Silver amalgam is used in Ayurvedic and Yunani medicines.

  3. Silver is used in silver plating.

  4. It is used in the preparation of silver salts used in silvering of mirrors, photography and medicine.

Show answer
Correct Option: C,D
Explanation:

The following are true regarding uses of silver.
Silver amalgam is used in filling teeth.
Silver leaves are used in Ayurvedic and Yunani medicines.
Silver is used in silver plating.
It is used in the preparation of silver salts used in silvering of mirrors, photography and medicine.

__and ___are alloys of copper.

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Brass and bronze

  2. Brass and alloy steel

  3. Copper pyrites and malachite

  4. Copper glance and cuprite

Show answer
Correct Option: A
Explanation:

  • A homogeneous mixture of two or more elements is known as Alloys.
  • There are various alloys of copper:
Brass-Copper with zinc, Bronze-Copper with tin, and Coinage alloy-copper with nickel.
  • Hence, option  A is correct.

Classify the following as physical or chemical properties.
The composition of a sample of steel is 98% iron, 1.5% carbon and 0.5% other elements.

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. Physical property

  2. Chemical property

  3. Both $A$ and $B$

  4. Neither $A$ or $B$

Show answer
Correct Option: A
Explanation:

Steel is an alloy of various metals, physically combined together in a fixed amount by weight, to improve the physical and mechanical properties.

Which of the following is/are true about silver plating?

chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. The process of depositing a thin layer of silver electrolytically on metal surface is called silver plating.

  2. The article to be silver plated is made the anode

  3. Cathode consists of pure silver.

  4. The bath contains a solution of potassium argentocyanide $(AgNO _3+ \text { excess of KCN})$

Show answer
Correct Option: A,D
Explanation:

The following are true about silver plating.
The process of depositing a thin layer of silver electrolytically on metal surface is called silver plating.
The article to be silver plated is made the cathode.
Anode consists of pure silver.
The bath contains a solution of potassium argentocyanide $(AgNO _3+ \text { excess of KCN})$

Match List - I (Position of the Metal in the Activity Series) with the List - II (Related Reduction Process) and select the correct option using the codes given below.

List - I(Position of the Metal in the Activity Series) List - II(Related Reduction Process)
(A) The bottom of the series (I) Electrolysis
(B) The top of the series (II) Reduction by heat alone
(C) The lower regions of the series (III) Found in native state
(D) The middle of the series (IV) Reduction using carbon or some other reducing agent
chemistry chemistry of non-metals physical properties of non-metals uses of metals and non metals physical properties of metals and non-metals

  1. $A - II, B - III, C - IV, D - I$

  2. $A - II, B - I, C - IV, D - III$

  3. $A - III, B - I, C - II, D - IV$

  4. $A - III, B - I, C - IV, D - II$

Show answer
Correct Option: C
Explanation:

The metals which are placed high in the reactivity series are obtained by electrolysis, middle metals by reduction using carbon, lower by heating alone and metals at bottom of the series are found in native state.