Physical Week 2

Question 1

What is ionic bonding?

Answer 1

Ionic bonding occurs when metals and non-metals react, resulting in the transfer of electrons from metal atoms to non-metal atoms and the formation of ions. The resulting compound is called an ionic compound.

Question 2

What are covalent bonds?

Answer 2

Covalent bonds occur when two non-metal atoms share a pair of electrons from their outer shells. This sharing of electrons allows each atom to complete its outer shell.

Question 3

What is dative bonding?

Answer 3

Dative bonding, also known as coordinate covalent bonding, is a type of covalent bond where both electrons in the shared pair come from the same atom. It occurs when one atom donates a lone pair of electrons to another atom.

Question 4

What is a hydroxonium ion?

Answer 4

The hydroxonium ion, also known as the hydronium ion or oxonium ion, is a positively charged ion composed of three hydrogen atoms and one oxygen atom. It is formed when a hydrogen ion (H+) attaches to a water molecule.

Question 5

What is a compound?

Answer 5

A compound is a substance composed of two or more different elements chemically bonded together. Compounds have unique properties that are different from the elements that make them up.

Question 6

What is an ionic compound?

Answer 6

An ionic compound is a compound formed through ionic bonding, where metal atoms donate electrons to non-metal atoms. The resulting compound consists of positively charged metal ions and negatively charged non-metal ions.

Question 7

Can you give examples of covalent compounds?

Answer 7

Examples of covalent compounds include hydrogen (H2), chlorine (Cl2), methane (CH4), hydrogen chloride (HCl), water (H2O), and oxygen (O2). Ammonia (NH3), carbon dioxide (CO2), and ethene (C2H4) are also examples of covalent compounds.

Question 8

What happens in dative covalent bonding?

Answer 8

In dative covalent bonding, only the hydrogen’s nucleus moves from chlorine to nitrogen, creating a negative chloride ion and a positive charge on the nitrogen atom.

Question 9

What is the difference between ionic bonding and covalent bonding?

Answer 9

Ionic bonding involves the transfer of electrons between atoms, while covalent bonding involves the sharing of electrons.

Question 10

How does dative bonding occur in NH3?

Answer 10

In dative bonding, a hydrogen ion is transferred from hydrogen chloride to the lone pair of electrons on the ammonia molecule, forming an ammonium ion (NH4+).

Question 11

What is ionic bonding and when does it occur?

Answer 11

Ionic bonding occurs when metals and non-metals react, resulting in the transfer of electrons and the formation of ions.

Question 12

What are the characteristics of materials with covalent bonds?

Answer 12

Materials with covalent bonds have strong bonds within molecules but weak forces of attraction between molecules, leading to low melting and boiling points.

Question 13

What are dative covalent bonds?

Answer 13

Dative covalent bonds, also known as coordinate covalent bonds, occur when both electrons in a shared pair come from the same atom.

Question 14

What happens once the ammonium ion is formed?

Answer 14

Once the ammonium ion is formed, it is indistinguishable from regular covalent bonds.

Question 15

How do covalent bonds form?

Answer 15

Covalent bonds form when two non-metal atoms share a pair of electrons, completing their outer shells.

Question 16

Can you provide examples of ionic bonding?

Answer 16

Examples of ionic bonding include reactions between magnesium and oxygen, calcium and chlorine, and sodium and chlorine.

Question 17

What is conductivity?

Answer 17

Conductivity refers to the ability of a material to conduct heat or electricity. Metals are excellent conductors of both heat and electricity due to the presence of delocalized electrons.

Question 18

What is a metallic bond?

Answer 18

The metallic bond is the attraction between free-moving (delocalized) electrons and positive metal ions. In metals, the outer shell electrons of metal atoms can move freely throughout the entire structure, creating a large structure.

Question 19

What is ductility?

Answer 19

Ductility is the property of a material that allows it to be drawn into thin wires without breaking. Metals are ductile because their structure allows for the movement of ions, which enables the metal to be stretched into a wire shape

Question 20

What is malleability?

Answer 20

Malleability is the property of a material that allows it to be bent, hammered, or pressed into different shapes without breaking. Most metals are malleable because their structure consists of layers of ions that can shift when external force is applied.

Question 21

What is the effect of the metallic bond on the physical properties of metals?

Answer 21

It keeps metals in an orderly arrangement and gives them high melting and boiling points

Question 22

How do metals create large structures?

Answer 22

Metals have large structures where electrons in the outer shells can move freely.

Question 23

What is the property of metals that allows them to be bent without breaking?

Answer 23

Most metals are malleable and can be bent without breaking.

Question 24

What happens to the ion layers in metals when they are bent or pressed?

Answer 24

The structure of metals allows ion layers to shift when the metal is bent or pressed.

Question 25

How does the number of outer electrons affect the melting and boiling points of metals?

Answer 25

Metals with more outer electrons have higher melting and boiling points.

Question 26

What property of metals makes them suitable for electrical cables?

Answer 26

Metals are ductile and can be pulled into wires, making them suitable for electrical cables.

Question 27

In what order do the melting and boiling points increase for Sodium, Magnesium, and Aluminium?

Answer 27

The melting and boiling points increase in the order: Sodium, Magnesium, Aluminium.

Question 28

What are bonding pairs?

Answer 28

Bonding pairs are pairs of electrons that are shared between atoms in a chemical bond. They contribute to the formation of covalent bonds, which are formed by the sharing of electrons between atoms.

Question 29

Describe the trigonal planar shape.

Answer 29

Trigonal planar is a molecular shape in which the atoms are arranged in a flat triangle. This shape occurs when there are three bonding pairs around the central atom with no lone pairs.

Question 30

Describe the shape of water.

Answer 30

Water (H2O) is a compound composed of two hydrogen atoms bonded to one oxygen atom. It has a bent or V-shaped molecular shape due to the presence of two bonding pairs and two lone pairs on the central oxygen atom.

Question 31

Describe the shape of ammonium.

Answer 31

The ammonium ion (NH4+) is a positively charged ion formed by the addition of a hydrogen ion (H+) to ammonia (NH3). It has a tetrahedral molecular shape, similar to methane, due to the presence of four bonding pairs around the central nitrogen atom.

Question 32

Describe the tetrahedral shape.

Answer 32

Tetrahedral is a molecular shape in which the atoms are arranged in a three-dimensional pyramid with a triangular base. This shape occurs when there are four bonding pairs around the central atom with no lone pairs.

Question 33

Describe the linear shape.

Answer 33

Linear is a molecular shape in which the atoms are arranged in a straight line. This shape occurs when there are only two atoms or when there are two bonding pairs around the central atom with no lone pairs.

Question 34

What are lone pairs?

Answer 34

Lone pairs are pairs of electrons that are not involved in bonding and are localized on a specific atom. They are also known as non-bonding pairs or unshared pairs.

Question 35

Describe the shape of ammonia.

Answer 35

Ammonia (NH3) is a compound composed of one nitrogen atom bonded to three hydrogen atoms. It has a tetrahedral molecular shape due to the presence of three bonding pairs and one lone pair on the central nitrogen atom.

Question 36

Describe the molecular shape of beryllium chloride (BeCl2).

Answer 36

Beryllium chloride (BeCl2) has a linear molecular shape with two bonding pairs positioned 180° apart.

Question 37

What is the molecular shape of water (H2O) and what is the bond angle?

Answer 37

Water (H2O) has a bent or V-shaped molecular shape with a bond angle of 104° caused by the repulsion between two lone pairs.

Question 38

What are the VSEPR geometries for simple molecules and ions?

Answer 38

The VSEPR geometries for simple molecules and ions include linear, trigonal planar, tetrahedral, trigonal pyramid, bent or angular, and square planar.

Question 39

What is the structure of the ammonium ion (NH4+) and why is it similar to methane?

Answer 39

The ammonium ion (NH4+) has a tetrahedral structure similar to methane due to its electronic arrangement.

Question 40

What is the molecular shape of boron trifluoride (BF3) and boron trichloride (BCl3)?

Answer 40

Boron trifluoride (BF3) and boron trichloride (BCl3) have a trigonal planar molecular shape with three pairs of electrons positioned 120° apart.

Question 41

What is the molecular shape of ammonia (NH3) and what is the bond angle?

Answer 41

Ammonia (NH3) has a tetrahedral molecular shape with a bond angle of 107° due to the repulsion between a lone pair and a bonding pair.

Question 42

How do lone pairs affect the bond angles in molecules and ions?

Answer 42

The presence of lone pairs can affect the bond angles in molecules and ions.

Question 43

If boron trifluoride (BF3) forms 3 bonds, similar to ammonia (NH3), what could be a possible effect on its molecular shape?

Answer 43

The presence of a lone pair could lead to more repulsion and alter the shape

Question 44

What are intramolecular forces?

Answer 44

Intramolecular forces are strong forces within a molecule, such as covalent bonds. These forces mainly affect the chemical properties of a compound.

Question 45

What are intermolecular forces?

Answer 45

Intermolecular forces are relatively weak attractions between molecules. They influence physical properties like boiling point, melting point, solubility, and viscosity.

Question 46

What are Van der Waals forces?

Answer 46

Van der Waals forces, also referred to as London forces or induced dipole forces, are a type of intermolecular force. These forces arise due to temporary changes in electron density, leading to the formation of temporary dipoles in molecules

Question 47

What are permanent dipole-dipole forces?

Answer 47

Permanent dipole-dipole forces are a type of intermolecular force that occurs between polar molecules. These forces are stronger than van der Waals forces and result from the attraction between the partial positive end of one molecule and the partial negative end of another molecule.

Question 48

What is hydrogen bonding?

Answer 48

Hydrogen bonding is a type of intermolecular force that occurs in compounds containing a hydrogen atom bonded to nitrogen, oxygen, or fluorine. These electronegative atoms must also have an available lone pair of electrons.

Question 49

What is a non-polar bond?

Answer 49

A non-polar bond is a covalent bond between atoms with equal or very similar electronegativities. The electron distribution in the bond is symmetrical, resulting in no permanent dipole across the molecule.

Question 50

What is a polar bond?

Answer 50

A polar bond is a covalent bond between elements with different electronegativities. The electron distribution in the bond is unsymmetrical, resulting in a permanent dipole across the molecule.

Question 51

What is electronegativity?

Answer 51

Electronegativity is the ability of an atom to attract the pair of electrons in a covalent bond towards itself. It is measured on the Pauling scale, which ranges from 0 to 4.

Question 52

If you have a molecule of 1-chloropropane and a molecule of pentane, which one would have a higher boiling point and why?

Answer 52

1-chloropropane would have a higher boiling point because it has both van der Waals forces and permanent dipole attractions, which are stronger than the van der Waals forces in pentane.

Question 53

What are intermolecular forces and how do they differ from intramolecular forces?

Answer 53

Intermolecular forces are weak attractions between molecules that influence physical properties, while intramolecular forces are strong forces within a molecule that affect chemical properties.

Question 54

What explains the increasing boiling points in the alkane homologous series?

Answer 54

The increasing boiling points in the alkane homologous series can be explained by the growing number of electrons and the shape of the molecule, leading to stronger van der Waals forces.

Question 55

If you were to compare the boiling points of H2O and H2S, which one would have a higher boiling point and why?

Answer 55

H2O would have a higher boiling point because it can form two hydrogen bonds due to the electronegative oxygen atom having two lone pairs of electrons, resulting in stronger hydrogen bonding.

Question 56

What is the significance of hydrogen bonding in intermolecular forces?

Answer 56

Hydrogen bonding is the strongest intermolecular force, contributing to higher boiling points and solubility in compounds like water and ethanol.

Question 57

How does the arrangement of polar bonds in a molecule determine its polarity?

Answer 57

The presence of polar bonds in a molecule can result in a permanent dipole, making the molecule polar. However, if the polar bonds are arranged symmetrically, the molecule can be non-polar.

Question 58

What are some effects of hydrogen bonding in substances?

Answer 58

Hydrogen bonding leads to the formation of regular structures in substances like ice and dimer formation in compounds like ethanoic acid.

Question 59

What is electronegativity and how does it relate to covalent bonds?

Answer 59

Electronegativity is the ability of an atom to attract electrons towards itself in a covalent bond. Polar bonds result from a difference in electronegativity, leading to a permanent dipole across the molecule.

Question 60

Why does iodine not conduct electricity and have low solubility in water?

Answer 60

Iodine does not conduct electricity and has low solubility in water due to its lack of charged particles and non-polar nature.

Question 61

What are the three main types of intermolecular forces and how are van der Waals forces influenced?

Answer 61

The three main types of intermolecular forces are van der Waals forces, permanent dipole-dipole forces, and hydrogen bonding. Van der Waals forces are influenced by the number of electrons in a molecule and are responsible for high melting and boiling points in molecular crystals like I2.

Question 62

What causes the attraction in hydrogen bonding?

Answer 62

Hydrogen bonding is characterised by the attraction between the small hydrogen atom and oxygen, nitrogen, or fluorine atoms due to their electronegativity difference.

Question 63

What are permanent dipole-dipole forces and how do they affect boiling points?

Answer 63

Permanent dipole-dipole forces are intermolecular forces, which are stronger than van der Waals forces, and result in compounds with higher boiling points.