Question

Explain the four basic types of chemical reactions. Be sure to include a sample equation for each type. Describe how rate relationships and activation energy are important in chemical reactions.

Answer 1

Synthesis, decomposition, single replacement and double replacement.

Synthesis- two or more reactants unite to form a single product

S (Sulfur) + O2 (Oxygen) ——> SO2 (Sulphur dioxide)

Decomposition- A single reactant is decomposed or broken down into two or more

CaCO3 (Calcium Carbonate) ——> CaO (Calcium oxide) + CO2 (Carbon dioxide)

Single replacement- A single free element replaces or is substituted for one of the elements in a compound. The free element is more reactive than the one its replaces.

Zn (Zinc) + 2 HCI (hydrochloric acid) ——> H2 (hydrogen) + ZnCl2 (Zinc Chloride)

Double replacement- This reaction type can be viewed as an "exchange of partners." For ionic compounds, the positive ion in the first compound combines with the negative ion in the second compound, and the positive ion in the second compound combines with the negative ion in the first compound.

HCI (hydrochloric acid) + NaOH (sodium hydroxide) ——> NaCl (Sodium Chloride) + HOH (water)


Once reactants have absorbed enough heat energy from their surroundings to reach the transition state, the reaction will proceed. The activation energy of a particular reaction determines the rate at which it will proceed. The higher the activation energy, the slower the chemical reaction will be.