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MTEL Chemistry study materials
MTEL Chemistry study resources

MTEL Chemistry: Chemistry Content Knowledge

MTEL Chemistry · Work through your exam, one topic at a time.

All guide sections

Chemistry Content Knowledge

Domain overview

The MTEL Chemistry content-knowledge domain tests reasoning across atomic structure, periodicity, bonding, stoichiometry, equilibrium, thermodynamics, and laboratory practice. Expect questions that ask you to predict products, calculate quantities from data, interpret graphs, and select safe procedures.

Core rules to master

  • Periodic trends: atomic radius decreases left-to-right and increases down a group; first ionization energy and electronegativity generally increase across a period and decrease down a group. Note the group 2→13 and group 15→16 dips caused by subshell changes and half-filled stability.
  • Bonding and shape: count electron domains to assign VSEPR geometry; polarity depends on both bond dipoles and geometry. Strongest intermolecular forces: hydrogen bonding > dipole–dipole > London dispersion (for similar-size particles).
  • Stoichiometry: convert mass→moles, use balanced coefficients, identify the limiting reactant, then convert to the requested quantity. Molarity = mol solute / L solution.
  • Equilibrium and acids: K expressions omit pure solids/liquids; Le Châtelier shifts oppose a stress. pH = −log[H3O+]; Kw = 1.0×10−14 at 25 °C.
  • Thermodynamics: ΔG = ΔH − TΔS; negative ΔG means spontaneous under stated conditions. Calorimetry: q = mcΔT.

Worked example

10.0 g CaCO3 (molar mass 100.09 g/mol) reacts with 100.0 mL of 1.00 M HCl: CaCO3(s) + 2HCl(aq) → CaCl2(aq) + CO2(g) + H2O(l). Moles CaCO3 = 10.0/100.09 = 0.0999 mol. Moles HCl = 0.1000 L × 1.00 mol/L = 0.100 mol. The equation requires 2 mol HCl per 1 mol CaCO3, so 0.0999 mol CaCO3 would need 0.1998 mol HCl; only 0.100 mol is present, so HCl is limiting. CO2 moles = 0.100 mol HCl × (1 CO2/2 HCl) = 0.0500 mol. Mass CO2 = 0.0500 × 44.01 = 2.20 g.

Traps that cost marks

  • Using a mass ratio where a mole ratio is required, or ignoring coefficients when finding the limiting reactant.
  • Confusing pH and pOH, or omitting pure solids/liquids from equilibrium expressions.
  • Assuming a polar bond always makes a polar molecule; bent and asymmetric shapes matter.
  • Forgetting that ionization-energy trends have exceptions, and that temperature can reverse ΔG predictions.
  • Choosing a procedure without checking safety and waste handling.