Edexcel Chemistry A-level Bonding and Structure Flashcards PDF

Edexcel Chemistry A-level Topic 2 - Bonding and Structure Flashcards PMT Education is licensed under https://bit.ly/pmt-cc This work by https://bit.ly/pmt-edu-cc CC BY-NC-ND 4.0...

Edexcel Chemistry A-level Topic 2 - Bonding and Structure Flashcards PMT Education is licensed under https://bit.ly/pmt-cc This work by https://bit.ly/pmt-edu-cc CC BY-NC-ND 4.0 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are ions? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are ions? Charged particles that is formed when an atom loses or gains electrons https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the charge of the ion when electrons are gained? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the charge of the ion when electrons are gained? Negative N.B - positive charge when electrons are lost E.g. 3+ ion has lost 3 electrons https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are molecular ions? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are molecular ions? Covalently bonded atoms that lose or gain electrons https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Which electrons are lost when an atom becomes a positive ion? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Which electrons are lost when an atom becomes a positive ion? Electrons in the highest energy levels https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Do metals usually gain or lose electrons? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Do metals usually gain or lose electrons? Lose electrons N.B - non-metals generally gain electrons https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Which are the 4 elements that don’t tend to form ions and why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Which are the 4 elements that don’t tend to form ions and why? The elements are beryllium, boron, carbon and silicon Requires a lot of energy to transfer outer shell electrons https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the 3 main types of chemical bonds? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the 3 main types of chemical bonds? Ionic Covalent Metallic https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define ionic bonding https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define ionic bonding The electrostatic attraction between positive and negative ions https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Give an example of a ionically bonded substance https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Given an example of an ionically bonded substance NaCl (Sodium Chloride - salt) https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  What determines the strength of an ionic bond? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What determines the strength of an ionic bond? - Ionic radius and ionic charge - Ionic bonding is stronger and the melting points higher when the ions are smaller and/ or have higher charges. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw the dot and cross diagram to show ionic bonding in MgO https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw the dot and cross diagram to show ionic bonding in MgO https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Explain the trend in ionic radius down a group https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Explain the trend in ionic radius down a group Ionic radii increases going down the group. This is because down the group the ions have more shells of electrons and thus the outermost electron experience less pull from positive nucleus. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Explain the trend in ionic radius for this set of isoelectronic ions, e.g. N3- to Al3+ https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Explain the trend in ionic radius for this set of isoelectronic ions, e.g. N3- to Al3+ There are increasing numbers of protons from N to F and then Na to Al but the same number of electrons. Therefore nuclear attraction between the outermost electrons and nucleus increases and ions get smaller https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the physical properties of ionic compounds? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the physical properties of ionic compounds? high melting points non conductor of electricity when solid conductor of electricity when in solution or molten brittle / https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc In a solution of CuCrO4 with connected electrodes which electrode will the 2 ions migrate to? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc In a solution of CuCrO4 with connected electrodes which electrode will the 2 ions migrate to? 2+ Cu - migrates to negative electrode CrO42- - migrates to positive electrode https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define covalent bonding https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define covalent bonding Electrostatic attraction between a shared pair of electrons and the nuclei https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Draw a dot and cross diagram for methane - CH4 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw a dot and cross diagram for methane https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Draw a dot and cross diagram for carbon dioxide - CO2 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw a dot and cross diagram for carbon dioxide https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Draw a dot and cross diagram for nitrogen - N2 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw a dot and cross diagram for nitrogen - N2 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define metallic bonding https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define metallic bonding Electrostatic attraction between the positive metal ions and the sea of delocalised electrons https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Electrons in which shell are represented in a dot and cross diagram? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Electrons in which shell are represented in a dot and cross diagram? The outer shell https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Why does giant ionic lattices conduct electricity when liquid but not when solid? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why does giant ionic lattices conduct electricity when liquid but not when solid? In solid state the ions are in fixed positions and thus cannot move. When they are in liquid state the ions are mobile and thus can freely carry the charge https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Giant ionic lattices have high or low melting and boiling point? Explain your answer https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Giant ionic lattices have high or low melting and boiling point? Explain your answer They have high melting and boiling point because a large amount of energy is required to overcome the electrostatic bonds https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc In what type of solvents do ionic lattices dissolve? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc In what type of solvents do ionic lattices dissolve? Polar solvents E.g water https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why are ionic compounds soluble in water? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why are ionic compounds soluble in water? Water has a polar bond. Hydrogen atoms + have a charge and oxygen atoms have a - charge. These charges are able to attract charged ions https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is it called when atoms are bonded by a single pair of shared electrons? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is it called when atoms are bonded by a single pair of shared electrons? Single bond https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How many covalent bonds does carbon form? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How many covalent bonds does carbon form? 4 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How many covalent bonds does oxygen form? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How many covalent bonds does oxygen form? 2 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the effect of multiple covalent bonds on bond length and strength? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the effect of multiple covalent bonds on bond length and strength? Double/triple bonds exert greater electron density therefore the attraction between nucleus and electron is greater resulting in a shorter and stronger bond. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is a lone pair? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is a lone pair? Electrons in the outer shell that are not involved in the bonding https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is formed when atoms share two pairs of electrons? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is formed when atoms share two pairs of electrons? Double bond https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  What is formed when atoms share three pairs of electrons? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is formed when atoms share three pairs of electrons? Triple bond https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is a dative covalent bond? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is a dative covalent bond? A bond where both of the shared electrons are supplied by one atom https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How are oxonium ions formed? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How are oxonium ions formed? Formed when acid is added to water, H 3O + https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw a dot and cross diagram to show bonding of Al2Cl6 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw a dot and cross diagram to show bonding of Al2Cl6 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What does expansion of the octet mean? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What does expansion of the octet mean? When a bonded atom has more than 8 electrons in the outer shell https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the types of covalent structure? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the types of covalent structure? Simple molecular lattice Giant covalent lattice https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Describe the bonding in simple molecular structures https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Describe the bonding in simple molecular structures? Atoms within the same molecule are held by strong covalent bonds and different molecules are held by weak intermolecular forces https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Why do simple molecular structures have low melting and boiling point? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why do simple molecular structures have low melting and boiling point? Small amount of energy is enough to overcome the intermolecular forces https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Can simple molecular structures conduct electricity? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Can simple molecular structures conduct electricity? No, they are non conductors. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why do simple molecular structures not conduct electricity? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why do simple molecular structures not conduct electricity? The have no free charged particles to move around https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Simple molecular structures dissolve in what type of solvent? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Simple molecular structures dissolve in what type of solvent? Non polar solvents https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Give examples of giant covalent structures https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Give examples of giant covalent structures Diamond Graphite Silicon dioxide, SiO2 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc List some properties of giant covalent structures? (3) https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc List some properties of giant covalent structures High melting and boiling point Non conductors of electricity, except graphite Insoluble in polar and non polar solvents https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How does graphite conduct electricity? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How does graphite conduct electricity? Delocalised electrons present between the layers are able to move freely carrying the charge https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Why do giant covalent structures have high melting and boiling point? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why do giant covalent structures have high melting and boiling point? Strong covalent bonds within the molecules need to be broken which requires a lot of energy https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw and describe the structure of a diamond https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw and describe the structure of a diamond 3D tetrahedral structure of C atoms, with each C atom bonded to four others https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What does the shape of a molecule depend on? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What does the shape of a molecule depend on? Number of electron pairs in the outer shell Number of these electrons which are bonded and lone pairs https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle for BeCl2 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle in a shape with 2 bonded pairs and 0 lone pairs? Linear 180° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle for BCl3? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle in a shape with 3 bonding pairs and 0 lone pairs? Trigonal planar 120° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle for CH4? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle in a shape with 4 bonded pairs and 0 lone pairs? Tetrahedral 109.5° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape,diagram and bond angle for PCl5? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle in a shape with 5 bonded pairs and 0 lone pairs? Trigonal bipyramid 90° and 120° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle for SF6? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle in a shape with 6 bonded pairs and 0 lone pairs? Octahedral 90° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle for NH3? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle in a shape with 3 bonded pairs and 1 lone pairs? Pyramidal 107° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle for H2O? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle in a shape with 2 bonded pairs and 2 lone pairs? Non linear 104.5° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram + and bond angle for NH4 https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the shape, diagram and bond angle for NH4+ Tetrahedral 109.5° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc By how many degrees does each lone pair reduce the bond angle? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc By how many degrees does each lone pair reduce the bond angle? 2.5° https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define electronegativity https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Define electronegativity The ability of an atom to attract the pair of electrons (the electron density) in a covalent bond https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  What scale is electronegativity measured on? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What scale is electronegativity measured on? Pauling scale https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  In which direction of the periodic table does electronegativity increase? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc In which direction of the periodic table does electronegativity increase? Top right, towards fluorine https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What does it mean when the bond is non-polar? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What does it mean when the bond is non-polar? The electrons in the bond are evenly distributed https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  What is the most electronegative element? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is the most electronegative element? Fluorine https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How is a polar bond formed? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How is a polar bond formed? Bonding atoms have different electronegativities https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why is H2O polar, whereas CO2 is non polar? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why is H2O polar, whereas CO2 is non polar? CO2 is a symmetrical molecule, so there is no overall dipole https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  What is meant by intermolecular force? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What is meant by intermolecular force? Attractive force between neighbouring molecules https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the 2 types of intermolecular forces? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What are the 3 types of intermolecular forces? Hydrogen bonding Permanent dipoles London forces https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Describe permanent dipole- induced dipole interactions https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Describe permanent dipole- induced dipole interactions When a molecule with a permanent dipole is close to other non polar molecules it causes the non polar molecule to become slightly polar leading to attraction https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Describe permanent dipole- permanent dipole interactions https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Describe permanent dipole- permanent dipole interactions Some molecules with polar bonds have permanent dipoles → forces of attraction between those dipoles and those of neighbouring molecules https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Describe London forces https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Describe London forces London forces are caused by random movements of electrons This leads to instantaneous dipoles Instantaneous dipole induces a dipole in nearby molecules Induced dipoles attract one another https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Are London forces greater in smaller or larger molecules? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Are London forces greater in smaller or larger molecules? Larger due to more electrons https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Does boiling point increase or decrease down the noble gas group? Why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Does boiling point increase or decrease down the noble gas group? Why? Boiling point increases because the number of electrons increases and hence the strength of London forces also increases https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What conditions are needed for hydrogen bonding to occur? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What conditions are needed for hydrogen bonding to occur? O-H, N-H or F-H bond, lone pair of electrons on O, F, N Because O, N and F are highly electronegative, H nucleus is left exposed Strong force of attraction between H nucleus and lone pair of electrons on O, N, F https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw a diagram of hydrogen bonding https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Draw a diagram of hydrogen bonding https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why is ice less dense than liquid water? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why is ice less dense than liquid water? In ice, the water molecules are arranged in a orderly pattern. It has an open lattice with hydrogen bonds. In water, the lattice is collapsed and the molecules are closer together. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Why does water have a melting/ boiling point higher than expected? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Why does water have a melting/ boiling point higher than expected? Hydrogen bonds are stronger than other intermolecular forces so extra strength is required to overcome the forces https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  What type of intermolecular forces do alkanes have? Why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What type of intermolecular forces do alkanes have? Why? London force → induced dipole-dipole interaction, because the bonds are nonpolar https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What happens to the boiling point as alkane chain length increases? Why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What happens to the boiling point as alkane chain length increases? Why? The boiling point increases because there is more surface area and so more number of induced dipole- dipole interaction. Therefore more energy required to overcome the attraction https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  Does a branched molecule have lower or higher boiling point compared to equivalent straight chain? Why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Does a branched molecule have lower or higher boiling point compared to equivalent straight chain? Why? The branched molecule has a lower boiling point because they have fewer surface area and hence less induced dipole -dipole interactions. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Are alkanes soluble in water? why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Are alkanes soluble in water? Explain your answer. Insoluble because hydrogen bonds in water are stronger than alkanes’ London forces of attraction https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What kind of intermolecular forces do alcohols have? Why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc What kind of intermolecular forces do alcohols have? Why? Hydrogen bonding, due to the electronegativity difference in the OH bond https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc  How do alcohols’ melting point and boiling point compare to other hydrocarbons’ of similar C chain lengths? Why? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc How do alcohols’ melting point and boiling point compare to other hydrocarbons’ of similar C chain lengths? Why? Higher, because they have hydrogen bonding (strongest type of intermolecular force) → stronger than London forces https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Are alcohols soluble in water? Why does solubility depend on chain length? https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Are alcohols soluble in water? Why does solubility depend on chain length? Soluble when short chain - OH hydrogen bonds to hydrogen bond in water Insoluble when long chain - non-polarity of C-H bond takes precedence https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Explain the trend of boiling temperatures of hydrogen halides HF to HI https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc Explain the trend of boiling temperatures of hydrogen halides HF to HI There is a general increase of boiling point from HCl to HI which is caused by increasing London forces because of increasing number of electrons. There is a big drop in boiling point from HF to HCl because fluorine is very electronegative therefore the hydrogen bonding is much stronger. https://bit.ly/pmt-cc https://bit.ly/pmt-edu https://bit.ly/pmt-cc