i. CaCO3(s) CaO(s) + CO2(g)

Here are the chemical concepts represented by each equation, along with short notes: i. CaCO_3(s) CaO_(s) + CO_2(g) Concept: Thermal Decomposition Note: This is a chemical reaction where a single compound breaks down into two or more simpler substances when subjected to heat. ii. 2NaOH_(aq) + H_2SO_4(aq) Na_2SO_4(aq) + 2H_2O_(l) Concept: Neutralization Reaction Note: This is a reaction between an acid and a base, which produces a salt and water. iii. CH_4(g) + Cl_2(g) CH_3Cl_(g) + HCl_(g) Concept: Substitution Reaction Note: In this type of reaction, an atom or a group of atoms in a molecule is replaced by another atom or group of atoms. iv. C_6H_12 C_6H_10 + H_2 Concept: Elimination Reaction (specifically Dehydrogenation) Note: This is a reaction where two atoms or groups are removed from a molecule, often resulting in the formation of a double or triple bond. In this specific case, hydrogen is removed. 3 done, 2 left today. You're making progress.