Reactions Types Definition: A reaction in which two or more substances combine to form a new, more complex substance.
General Equation:
$$ A + B → C $$ Types of Synthesis Reactions:
- Direct Combination: Two elements combine directly to form a compound.
$$ 2 Na + Cl2 → 2 NaCl $$ * Combination of Oxides: Two metal oxides react to form a new metal oxide.
$$ CaO + SiO_2 → CaSiO_3 $$ * Combination of Halides: Two metal halides react to form a new metal halide.
$$ 2 NaCl + PbCl_2 → PbCl_4 + 2 Na $$ * Combination of Acid and Base: An acid and a base react to form a salt and water.
$$ HCl + NaOH → NaCl + H_2O $$ Predicting Products of Synthesis Reactions:
- Metal + Nonmetal: Forms an ionic compound with the metal as the cation and the nonmetal as the anion.
- Metal Oxide + Nonmetal Oxide: Forms a new metal oxide.
- Metal Halide + Nonmetal Halide: Forms a new metal halide.
- Acid + Base: Forms a salt and water.
Example Problems:
1. Predict the products of the following reaction:
$$ Li + F_2 → $$
Solution:
$$ Li + F_2 → 2 LiF $$
2. Calculate the mass of copper(II) oxide produced when 10.0 g of copper reacts with excess oxygen gas.
$$ 2 Cu + O2 → 2 CuO $$ $$ 10.0 g Cu × \left(\frac{1 \text{ mol Cu}}{63.55 \text{ g Cu}}\right) × \left(\frac{2 \text{ mol CuO}}{2 \text{ mol Cu}}\right) × \left(\frac{79.55 \text{ g CuO}}{1 \text{ mol CuO}}\right) = 12.7 g CuO $$