International Baccalaureate IB Chemistry

Elements are the primary constituents of matter, which cannot be chemically broken down into simpler substances.

Compounds consist of atoms of different elements chemically bonded together in a fixed ratio. 

Mixtures contain more than one element or compound in no fixed ratio, which are not chemically bonded and so can be separated by physical methods. Distinguish between the properties of elements, compounds and mixtures.

Kinetic molecular theory and states of matter

The kinetic molecular theory is a model to explain physical properties of matter (solids, liquids and gases) and changes of state. 

Distinguish the different states of matter. Use state symbols (s, l, g and aq) in chemical equations. 

Names of the changes of state should be covered: melting, freezing, vaporization (evaporation and boiling), condensation, sublimation and deposition.

The temperature, $T$, in Kelvin ($K$) is a measure of average kinetic energy ($E_k$) of particles.

Interpret observable changes in physical properties and temperature during changes of state. 

Convert between values in the Celsius and Kelvin scales. 

The kelvin ($K$) is the SI unit of temperature and has the same incremental value as the Celsius degree ($^\circ\mathrm{C}$).

Atoms contain a positively charged, dense nucleus composed of protons and neutrons (nucleons). Negatively charged electrons occupy the space outside the nucleus.

Use the nuclear symbol $^{A}_{Z}\text{X}$ to deduce the number of protons, neutrons and electrons in atoms and ions. 

Relative masses and charges of the subatomic particles should be known; actual values are given in the data booklet. The mass of the electron can be considered negligible.

Isotopes are atoms of the same element with different numbers of neutrons.

Perform calculations involving non‑integer relative atomic masses and abundance of isotopes from given data. 

Differences in the physical properties of isotopes should be understood. Specific examples of isotopes need not be learned.

Interpret mass spectra in terms of identity and relative abundance of isotopes. The operational details of the mass spectrometer will not be assessed.

Qualitatively describe the relationship between colour, wavelength, frequency and energy across the electromagnetic spectrum.

Distinguish between a continuous and a line spectrum. Details of the electromagnetic spectrum are given in the data booklet.

Describe the emission spectrum of the hydrogen atom, including the relationships between the lines and energy transitions to the first, second and third energy levels.

The names of the different series in the hydrogen emission spectrum will not be assessed.

Deduce the maximum number of electrons that can occupy each energy level.

Recognize the shape and orientation of an s atomic orbital and the three p atomic orbitals.

Apply the Aufbau principle, Hund’s rule and the Pauli exclusion principle to deduce electron configurations for atoms and ions up to Z = 36.

Full electron configurations and condensed electron configurations using the noble gas core should be covered. 
Orbital diagrams should be used to represent the filling and relative energy of orbitals. 

The electron configurations of Cr and Cu as exceptions should be covered.

Explain the trends and discontinuities in first ionisation energy ($IE$) across a period and down a group.

Calculate the value of the first $IE$ from spectral data that gives the wavelength or frequency of the convergence limit. 

The value of the Planck constant $h$ and the equations $E = hf$ and $c = \lambda f$ are given in the data booklet.

Successive ionisation energy and group identification
Deduce the group of an element from its successive ionisation data.

Convert the amount of substance, $n$, to the number of specified elementary entities.

An elementary entity may be an atom, a molecule, an ion, an electron, any other particle or a specified group of particles. 

The Avogadro constant $N_A$ is given in the data booklet. It has the units $\mathrm{mol^{-1}}$.

Determine relative formula masses $M_r$ from relative atomic masses $A_r$. No units.

The values of relative atomic masses given to two decimal places in the data booklet should be used in calculations.

Solve problems involving the relationships between the number of particles, the amount of substance in moles and the mass in grams.

Interconvert the percentage composition by mass and the empirical formula.

Determine the molecular formula of a compound from its empirical formula and molar mass.

Solve problems involving the molar concentration, amount of solute and volume of solution.

The use of square brackets to represent molar concentration is required. Units of concentration should include $g\,\text{dm}^{-3}$ and $mol\,\text{dm}^{-3}$ and conversion between these. The relationship $n = c V$ is given in the data booklet.

Solve problems involving the mole ratio of reactants and/or products and the volume of gases.

An ideal gas consists of moving particles with negligible volume and no intermolecular forces.

All collisions between particles are considered elastic.

Recognize the key assumptions in the ideal gas model.

Explain the limitations of the ideal gas model.

Investigate the relationship between temperature, pressure and volume for a fixed mass of an ideal gas and analyse graphs relating these variables.

Solve problems relating to the ideal gas equation. Units of volume and pressure should be SI only.