Chemical Bond and Molecular Structure MCQ Quiz - Objective Question with Answer for Chemical Bond and Molecular Structure - Download Free PDF

The correct answer is Quick lime.

Explanation:

• The chemical formula for quick lime calcium oxide is CaO.
• It reacts with water to form calcium hydroxide.
• The product was left immediately after the calcination of pure limestone.
• It is commonly used in making porcelain and glass and also in preparing bleaching powder
• Limestone forms from the accumulation of shell, coral, algal, and fecal debris that have calcium carbonate in them.
• The chemical composition of chalk is calcium carbonate, with minor amounts of silt and clay.
• Marble (Calcium carbonate) is a biogenic rock and is more compact than chalk.
• As with marble, calcium carbonate is a coarse-crystalline, metamorphic rock that is formed when chalk or limestone is recrystallized under conditions of high temperature and pressure.

The correct answer is They form between non-metals.

Key Points

• Covalent bonds form between non-metals.
• Covalent bonds involve the sharing of electrons, not the loss of electrons. When atoms lose electrons, they form ionic bonds, not covalent bonds. .
• Covalent bonds do not involve the transfer of electrons, which is characteristic of ionic bonds.
• Covalent bonds typically have lower melting and boiling points compared to ionic bonds.
• These bonds can form single, double, or triple bonds, depending on the number of shared electron pairs.

Additional Information

• Ionic Bonds
  • Formed between a metal and a non-metal.
  • Involve the transfer of electrons from one atom to another.
  • Result in the formation of positively and negatively charged ions.
  • Typically have high melting and boiling points.
• Metallic Bonds
  • Formed between metal atoms.
  • Involve a 'sea of electrons' that are free to move around.
  • Responsible for the conductivity and malleability of metals.
• Polar Covalent Bonds
  • A type of covalent bond where electrons are shared unequally.
  • Results in a molecule having a partial positive charge on one end and a partial negative charge on the other.
  • Water (H₂O) is a common example of a molecule with polar covalent bonds.
• Non-Polar Covalent Bonds
  • Electrons are shared equally between atoms.
  • Occurs typically between atoms of the same element.
  • Molecules like O₂ and N₂ are examples of non-polar covalent bonds.

The correct answer is They have weak intermolecular forces.

Key Points

• Covalent compounds are formed by the sharing of electrons between atoms.
• These compounds usually have low melting and boiling points due to the presence of weak intermolecular forces.
• The individual molecules are held together by Van der Waals forces or dipole-dipole interactions, which are much weaker than ionic or metallic bonds.
• As a result, it requires less energy to overcome these forces, leading to lower melting and boiling points.
• Examples of covalent compounds with low melting and boiling points include water (H₂O), methane (CH₄), and carbon dioxide (CO₂).

 Additional Information

• Metallic Bonds
  • Metallic bonds are characterized by a 'sea of electrons' that are free to move around.
  • This type of bonding leads to high melting and boiling points as the bonds are strong and require more energy to break.
• Electrostatic Forces
  • Electrostatic forces are the forces between charged particles, such as ions.
  • In ionic compounds, these forces are very strong, resulting in high melting and boiling points.
• Rigid Lattice Structure
  • A rigid lattice structure is typically found in ionic compounds and some covalent network solids like diamond.
  • This structure contributes to high melting and boiling points due to the strong bonds that hold the lattice together.

The correct answer is Copper Sulphate.

Key Points

• Copper Sulphate, commonly known as Blue Vitriol, is a chemical compound with the formula CuSO₄.
• The compound is widely used as a fungicide, insecticide, and herbicide in agricultural practices.
• Copper Sulphate exists in its pentahydrate form (CuSO₄·5H₂O), which gives it a distinct blue color.
• It is extensively used as a mordant in the textile industry to fix dyes to fibers.
• Other applications include its use in electroplating processes and as a reagent in laboratories.

Additional Information

• Fungicides:
  • Fungicides are chemical or biological agents used to kill or inhibit fungi and fungal spores.
  • Copper-based fungicides like Copper Sulphate are effective against plant diseases such as mildew and blight.
• Mordants:
  • A mordant is a substance used to fix dyes onto fabrics, ensuring color durability and retention.
  • Copper Sulphate is a commonly used mordant in the textile and leather industries.
• Industrial Uses:
  • Copper Sulphate is used in electroplating to coat surfaces with a thin layer of copper.
  • It is also utilized in the preparation of pigments like copper-based blues and greens.
• Environmental Concerns:
  • Excessive use of Copper Sulphate can lead to soil and water contamination.
  • It is toxic to aquatic life if discharged untreated into water bodies.

The correct answer is NaCl.Key Points

• Ionic Bond: These bonds are also called Electrovalent bond.
• This type of linkage formed from the electrostatic attraction between oppositely charged ions in a chemical compound.
• The atom that loses the electrons becomes a positively charged ion (cation), while the one that gains them becomes a negatively charged ion (anion).
• The formation of ionic compounds (like the addition of sodium metal and chlorine gas to form NaCl) are usually extremely exothermic.
• The loss of an electron from an element.
  • Always endothermic (takes energy to strip the electron from the atom)
• The gain of an electron by a non-metal:
  • Generally exothermic (energy released)
• Ionic bond can be both Endothermic and exothermic.
• Examples - KCl, AlCl3, NaCl

Additional Information

Covalent Bond:

• A covalent connection is created when the electrons from each participating atom are shared equally.
• Shared pair or bonding pair refers to the pair of electrons involved in this sort of bonding.
• Molecular bonds are another name for covalent bonding.
• The atoms will gain stability in their outer shell through the sharing of bonding pairs, analogous to noble gas atoms.
• Examples - CH4, H2O, NH3

The correct answer is Vermilion.

• Mercury Sulfide is also known as Vermilion.
• It is a chemical compound composed of the chemical elements mercury and sulfur.
• The chemical formula of Mercury sulfide is HgS.
• It is dimorphic with two crystal forms:
  • Red cinnabar
  • Black metacinnabar

Additional Information

• Marsh Gas is the common name of Methane with the formula of CH₄.
• Mohr's Salt is the common name of Ammonium Ferrous Sulphate with the formula of (NH₄)2Fe(SO₄)₂(H₂O)₆.
• Potash Alum is the common name of Potassium Aluminium Sulphate with the formula of KAl(SO₄)₂.

• Amphoteric oxides are the oxides which can react with both acids and base.
• For example, Aluminium oxide (Al₂O₃).
• Aluminium oxide reacts with acids like hydrochloric acid (HCl) and bases like sodium hydroxide (NaOH), to form salt and water.

Al₂O₃ + 6 HCl → 2Al₂Cl₃ + 3H₂O

(Salt)

Al₂O₃ + 2 NaOH → 2 NaAlO₂ + H₂O

(Salt)

The correct answer is Covalent bond.

Important Points

• Graphite has a giant covalent structure in which: each carbon atom is joined to three other carbon atoms by covalent bonds.
  • The bonds which are formed by the medium of mutual sharing of electrons are called covalent bonds.

Additional Information

• When the complete transfer of the valence electron takes place, the bond formed is called the Ionic Bond.
• The partial intermolecular bonding of the lone pair of electrons in the second-row elements like nitrogen, oxygen, or fluorine is called a Hydrogen bond.
• Van der Waals bond is basically a secondary bond which is a weak force of attraction between electrically neutral molecules that collide with or pass very close to each other.

The correct answer is Silver Nitrate.

• Silver Nitrate is an inorganic compound also known as Lunar Caustic with the formula of AgNO₃.
• It is used in photography. It is also less light-sensitive than halides.
• It was once called lunar caustic, since the ancient alchemists, who linked silver with the moon, called silver luna.
• In solid silver nitrate, in a trigonal planar structure, silver ions are three-coordinated.
• Silver nitrate can be treated with nitric acid by reacting with silver, such as silver bullion or silver foil, resulting in silver nitrate, water, and nitrogen oxides. The by-products of the reaction depend on the nitric acid concentration used.

3 Ag + 4 HNO3 (cold and diluted) → 3 AgNO3 + 2 H2O + NO    

Ag + 2 HNO3 (hot and concentrated) → AgNO3 + H2O + NO2

Additional Information

• The common name of Sodium Hydroxide(NaOH) is Caustic Soda.
• The Common name of Hydrochloride Acid(HCl) is Muriatic acid.
• The Common name of Calcium Oxide(CaO) is Lime.

The correct answer is Quick lime.

Explanation:

• The chemical formula for quick lime calcium oxide is CaO.
• It reacts with water to form calcium hydroxide.
• The product was left immediately after the calcination of pure limestone.
• It is commonly used in making porcelain and glass and also in preparing bleaching powder
• Limestone forms from the accumulation of shell, coral, algal, and fecal debris that have calcium carbonate in them.
• The chemical composition of chalk is calcium carbonate, with minor amounts of silt and clay.
• Marble (Calcium carbonate) is a biogenic rock and is more compact than chalk.
• As with marble, calcium carbonate is a coarse-crystalline, metamorphic rock that is formed when chalk or limestone is recrystallized under conditions of high temperature and pressure.

Ethylene has a double bond because it consists of two carbon atoms that are double-bonded to each other. Its chemical formula is C₂H_4.

• Benzene was isolated by Michael Faraday in the year 1825.
• The molecular formula of benzene is C₆H₆, indicates a high degree of unsaturation.
• 
• Benzene has 12 σ and 3 π bonds.

The correct answer is Si.

Important Points

• Catenation is the binding of an element to itself through covalent bonds to form chain or ring molecules.
• Carbon is the most common element that exhibits catenation.
  • It can form long hydrocarbon chains and rings like benzene.
• Please note that the smaller the atom, the stronger the tendency of catenation.
• All the elements of the carbon family or group 4 family exhibit catenation property.
• The carbon family includes carbon (C), silicon (Si), germanium (Ge), tin (Sn), lead (Pb), and flerovium (Fl).
• The ability of an element to catenate is primarily based on the bond energy of the element to itself, which decreases with more diffuse orbitals.
• The bond length decreases across a row in the periodic table and increases down a group.
• The bond energy of S-S is 266 Kj/mol. 
• The bond energy of Si-Si is 340 Kj/mol.
• The bond energy of P-P is 54 Kj/mol.
• The bond energy of N-N is 160 Kj/mol.

Additional Information

• Catenation tendency decreases down the group.
• This happens because the atomic size increases down the group and the strength of the covalent bond decreases.

The correct answer is Option 3, i.e CaSO₄.1/2 H₂O

• The chemical name of the Plaster of Paris is calcium sulphate hemihydrate.
• The chemical formula of the Plaster of Paris is CaSO₄.1/2 H₂O.
• Plaster of Paris is a quick-setting gypsum plaster which is composed of a fine white powder (calcium sulfate hemihydrate), that hardens when moistened and allowed to dry.
• CH3COOH is Acetic Acid.
• (NH4)2SO4 is Ammonium Sulfate.

• Nickel (Ni) is used as a catalyst in the hydrogenation of Vegetable oil.
• Hydrogenation gives us edible fats like Vanaspati.
• Catalyst: It is a substance which increases the rate of a chemical reaction without undergoing any change in its chemical properties.
• Dihydrogen (H₂) is used during the synthesis of ammonia and manufacture of Vanaspati by hydrogenation of polyunsaturated oils.