Chemical Bonding

Chemical Bonding

Multiple Select

What does chemical bonding involve?

• The sharing of electrons.

• The gaining of electrons.

• The switching of electrons.

• The losing of electrons.

Multiple Choice

Noble gases are reactive.

True or False?

• True

• False

• Huh?

Multiple Choice

What is the outer shell of 8 electrons called?

• an octave structure

• an oclet structure

• an octet structure

• an octent structure

Multiple Select

Select the types of bonding.

• metallic bonding

• covalent bonding

• non-metallic bonding

• ionic bonding

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Multiple Select

What can we know by looking at a chemical formula? I.e. H₂O

• the ratio between the elements

• the elements present

• how many people have touched it

• why it is black

Multiple Select

What are the names of the three main types of chemical formulae?

• molecular formula

• impirical formula

• structural formula

• empirical formula

• diagrammatic formula

​Chemical Formulae Of Compounds

• The molecular formula: uses subcripts to give the actual number of atoms of each element present in one molecule of a compound. E.g., water is H₂O, which means one molecule of water contains 2 hydrogen atoms and 1 oxygen atom. Another example is CO₂ for carbon dioxide and C₆H₁₂O₆ for glucose.

• The structural formula: a diagrammatic representation of one molecule of the compound using lines between the atoms to represent bonds. E.g., CO₂ is O=C=O. This shows that there are two bonds between each oxygen atom and the carbon atom.

​​Chemical Formulae Of Compounds Cont.

• ​The empirical formula: gives the simplest whole number ratio between the elements in the compound using subscripts. The compound consists of multiples of these smallest units. E.g. magnesium chloride is MgCl₂. This tells us that magnesium and chloride are present in a ratio of 1 to 2.

​If You Still Don't Full Understand The Differences

1. ​This is the structural formula for Ethane. Carbon has 4 electrons on the outside. One at the top, bottom, left and right. Carbon and hydrogen are non-metals so they'd bond covalently, meaning they'd share electrons. Carbon and carbon would share one, so now both carbons have 5 electrons on their valence shell. Hydrogen comes in with 1 electron and gives both carbon the remaining 3.

​2. The molecular formula would tell how many of each atom is present. There are 6 hydrogen atoms and 2 carbon atoms so - C₂H₆

​3. The empirical formula wants you to find the highest common factors though. The highest common factor of 2 and 6 is 2. You'd divide the 2 and 6 by 2 and get 1 and 3. We don't write the 1 so you'd just see the 3. So - CH₃. Don't say this on the test though. We'll go through the steps to write the formula soon.

Multiple Choice

Identify the type of chemical formula.

This gives the simplest whole number ratio between the elements in the compound using subscripts. I.e. MgCl₂

• Impirical formula

• Molecular formula

• Structural formula

• Empirical formula

• Mole formula

Multiple Choice

Identify the type of chemical formula.

Gives the actual number of atoms of each element present in one molecule of a compound. I.e. C₆H₁₂O₆

• Molecular formula

• Impirical formula

• Structural formula

• Empirical formula

• Mole formula

Multiple Choice

Identify the type of chemical formula.

Gives the diagrammatic representation of one molecule of the compound. Lines

between the atoms are used to represent bonds

• Molecular formula

• Impirical formula

• Structural formula

• Empirical formula

• Mole formula

Multiple Choice

How does chlorine become chloride? What charge does it get?

• Chlorine gains 1 electron and gets a positive charge.

• Chlorine loses 1 electrons and gets a negative charge.

• Chlorine gains 1 electrons and gets a neutral charge.

• Chlorine loses 1 electron and gets a positive charge.

• Chlorine gains 1 electrons and gets a negative charge.

Multiple Choice

How does magnesium become an ion? What charge does it get?

• Magnesium loses 2 and gets a negative charge.

• Magnesium loses 2 and gets a positive charge.

• Magnesium gains 2 and gets a negative charge.

Multiple Choice

When the chloride ion and the magnesium ion bonds, what kind of bonding is it?

• Ionic

• Covalent

• Metallic

• Non-metallic

Multiple Choice

(In relation to previous question) Why is it ionic bonding?

• Because they are both metals.

• Because they are both nonmetals.

• Because chlorine is a metal and magnesium is a non-metal.

• Because magnesium is a metal and chlorine is a non-metal.

Multiple Choice

An ionic bond is defined as...?

• the electrostatic attraction between positively charged ions.

• the electrostatic attraction between negatively charged ions.

• the electrostatic attraction between oppositively charged ions.

• the electrostatic attraction between ions of the same charge.

​Covalent Bonding

Sharing of electrons:

• Two hydrogens atoms join together and share their electrons. A hydrogen molecule is formed.

• ​Two oxygen atoms combine to share 4 electrons. This is called a double bond.

​Properties of Covalent Compounds

• Non-metals bond covalently. Non-metals have a low melting and boiling point so naturally, a property of covalent compounds is: low boiling and melting points.​

• ​It has low points because the intermolecular forces between the molecules are weak.

• ​E.g. Water (a covalent compound) has a low melting point of 0 degrees and a low boiling point of 100 degrees.

​​Properties of Covalent Compounds Cont.

• Most non-metals do not conduct electricity so naturally a property of covalent bonds is the inability to conduct electricity in any state.

• Most covalent compounds are insoluble in water. Instead they are soluble in organic solvents.

• ​E.g. Iodine is insoluble in water but soluble in ethanol (an organic solvent).​

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​Note: Pure water doesn't conduct electricity.

​NB: Inorganic solvents are those solvents which do not contain carbon such as water, ammonia whereas organic solvents are those solvents which contain carbon and oxygen in their composition such as alcohols, glycol ethers.

​Properties of Ionic Compounds

Ionic compounds are made of a metal and a non-metal. Metals have a positive charge and non-metals have a negative charge.​ So naturally a property of ionic compounds is having a very strong electrostatic force.

​

• The electrostatic forces between the oppositely-charged ions are very strong so ionic compounds have very high melting points and boiling points.

• ​Ionic compounds have very high melting points and boiling points.

  For e.g. sodium chloride has a melting point of 801 degrees and a boiling point of 1517 degrees celcius.

​​Properties of Ionic Compounds

• All ionic compounds conduct electricity when molten or dissolved in water.​

• ​This is because the ions can move about and conduct electricity.

• ​Most ionic compounds are soluble in water, but insoluble in organic solvents. For e.g. sodium chloride is soluble in water, but insoluble in oil or petrol.

Multiple Choice

What is substance B?

• a covalent compound

• a metal

• an ionic compound

Multiple Choice

What is substance A?

• a covalent compound

• a metal

• an ionic compound

Multiple Choice

What is substance C?

• a covalent compound

• a metal

• an ionic compound

Multiple Choice

Sugar is a covalent compound but it is soluble in water. State one test you would use to show that sugar is a covalent compound.

• Dissolve some sugar in water, then try to pass electricity through it. The sugar solution will not able to conduct electricity.

• Dissolve some sugar in water, then try to pass electricity through it. The sugar solution will be able to conduct electricity.

Multiple Choice

Do covalent compounds have a high or low melting point?

• high

• low

Multiple Choice

Do covalent compounds have a high or low boiling point?

• high

• low

Multiple Choice

Why do covalent compounds have a low melting point and boiling point?

• There are too many intermolecular forces between the molecules.

• There are no intermolecular forces between the molecules.

• The intermolecular forces between the molecules are strong.

• The intermolecular forces between the molecules are weak.

Multiple Choice

Do ionic compounds have a high or low boiling point?

• high

• low

Multiple Choice

Do ionic compounds have a high or low melting point?

• low

• high

Multiple Choice

Why do ionic compounds have a high melting point and boiling point?

• The electrostatic forces between the oppositely-charged ions are very strong.

• The electrostatic forces between the oppositely-charged ions are repelling.

• The electrostatic forces between the oppositely-charged ions are.

• The electrostatic forces between the oppositely-charged ions are very weak.

Multiple Select

When do all ionic compounds conduct electricity?

• when molten

• when solid

• when liquid

• when dissolved