This laboratory experiment consists of the synthesis of two series of alkaline-earth titanates (calcium-strontium and strontium-barium)to corroborate Vegard's law by obtaining their X-ray diffraction patterns and plotting the lattice parameter versus mole fraction of both cations. This experiment allows students to understand the key concepts in the solid state chemistry of a lattice parameter, a cubic Bravais network, a perovskite type structure, substitutional solid solutions, Vegard's law and its deviations, Miller indices, and X-ray diffraction principles. In addition, it gives students the opportunity to acquire technical skills in ceramic synthesis and X-ray diffraction pattern interpretation.