VCE Chemistry Unit 2 AOS 1 | Free VCE Resources

The Unique Physical Properties of Water

This section explores how water’s molecular structure—its shape and polarity—leads to the formation of strong hydrogen bonds. These bonds are responsible for water’s anomalous properties, such as its high boiling point and ability to absorb large amounts of heat. Use the interactive elements below to visualize these concepts.

Molecular Shape & Polarity

A molecule’s shape determines if bond polarities cancel out. Water’s bent shape makes it polar, while CO₂’s linear shape makes it non-polar. This is a key reason for their different properties.

Select a molecule to see its properties.

Heat Calculation Practice

Water’s high specific heat capacity and latent heat values are due to hydrogen bonding. Use this tool to practice the calculations involved.

Calculation Type

Mass (g) Temp. Change (°C)

Result will appear here.

Anomaly: Boiling Points of Group 16 Hydrides

While boiling points typically increase down a group due to stronger dispersion forces, water breaks this trend dramatically. Its boiling point is anomalously high because of strong hydrogen bonding, which requires much more energy to overcome compared to the forces in H₂S, H₂Se, and H₂Te.

Water as the Universal Solvent

Water’s polarity makes it an excellent solvent for ionic and polar substances. This section demonstrates how water molecules interact with solutes to cause dissolution and how mixing ionic solutions can lead to precipitation. Explore the ‘like dissolves like’ principle and predict reaction outcomes.

Visualizing Dissolution

For a substance to dissolve, the solute-solvent attractions must be strong enough to overcome solute-solute and solvent-solvent attractions. Water dissolves ionic compounds via ion-dipole attractions and polar molecules via hydrogen bonding.

Select a scenario to visualize.

Precipitation Reaction Predictor

When two soluble ionic solutions are mixed, an insoluble precipitate can form. Select two reactants to see if a reaction occurs and to identify the precipitate and spectator ions.

Reactant 1

Reactant 2

Result:

Select reactants and predict.

Acid-Base Chemistry in Water

Water is central to acid-base chemistry, often acting as a reactant itself. This section clarifies the key distinctions between strong/weak and concentrated/dilute solutions, and provides an interactive tool to explore the pH scale and the effect of dilution.

Strength vs. Concentration

These terms are often confused. **Strength** refers to the degree of ionisation (an intrinsic property). **Concentration** refers to the amount of solute in a volume (a prepared property). Click the buttons to explore the four possible combinations.

Select a type

An explanation will appear here.

pH & Dilution Calculator

Calculate the pH of a strong acid or base and see how dilution affects it. Remember, diluting an acid increases its pH towards 7, while diluting a base decreases its pH towards 7.

Solution Type

Initial Concentration (M)

Final Volume (mL) after adding water to 10mL initial

Initial pH: –

Final pH after Dilution: –

An Introduction to Redox Reactions

Redox reactions involve the transfer of electrons. This section provides a guided tool for balancing complex redox equations in acidic solutions—a critical skill in VCE Chemistry. It also demonstrates a simple metal displacement reaction.

Metal Displacement Reaction

A more reactive metal will displace a less reactive metal’s ions from solution. Here, a strip of zinc (a stronger reductant) is placed in a solution of copper(II) sulfate.

Click “Run Reaction” to see what happens.

Redox Equation Balancer

Practice balancing redox equations using the half-equation method for acidic conditions. Follow the steps for the reaction between permanganate and iron(II) ions.

Unbalanced: MnO₄⁻(aq) + Fe²⁺(aq) → Mn²⁺(aq) + Fe³⁺(aq)