List and define three categories of chemical reactions?

Answer 1

CHEMICAL reactions can be classified into categories;

SYNTHESIS REACTION

In a synthesis reaction two or more simple substances combine to form a more complex substance. Two or more reactants yielding one product is another way to identify a synthesis reaction.

For example, simple hydrogen gas combined with simple oxygen gas can produce a more complex substance-----water!

The chemical equation for this synthesis reaction looks like:

reactant + reactant -------> product

To visualize a synthesis reaction look at the following cartoon:

In the cartoon, the skinny bird (reactant) and the worm (reactant) combine to make one product, a fat bird.

DECOMPOSITION REACTION

In a decomposition reaction a more complex substance breaks down into its more simple parts. One reactant yields 2 or more products. Basically, synthesis and decomposition reactions are opposites.

For example, water can be broken down into hydrogen gas and oxygen gas. The chemical equation for this decomposition reaction looks like:

reactant -------> product + product

To visualize a decomposition reaction look at the following cartoon:

In this cartoon the egg (the reactant), which contained the turtle at one time, now has opened and the turtle (product) and egg shell (product) are now two separate substances.

SINGLE REPLACEMENT REACTION

In a single replacement reaction a single uncombined element replaces another in a compound. Two reactants yield two products. For example when zinc combines with hydrochloric acid, the zinc replaces hydrogen. The chemical equation for this single replacement reaction looks like:

reactant + reactant ---------> product + product

To visualize a single replacement reaction look at the following cartoon:

Notice, the guy in the orange shirt steals the date of the other guy. So, a part of one of the reactants trades places and is in a different place among the products.

DOUBLE REPLACEMENT REACTION

In a double replacement reaction parts of two compounds switch places to form two new compounds. Two reactants yield two products. For example when silver nitrate combines with sodium chloride, two new compounds--silver chloride and sodium nitrate are formed because the sodium and silver switched places. The chemical equation for this double replacement reaction looks like:

reactant + reactant ---------> product + product

To visualize a double replacement reaction look at the following cartoon:

ENERGY OF CHEMICAL REACTIONS

Chemical reactions always involve a change in energy. Energy is neither created or destroyed. Energy is absorbed or released in chemical reactions. Chemical reactions can be described as endothermic or exothermic reactions.

Endothermic Reactions

Chemical reactions in which energy is absorbed are endothermic. Energy is required for the reaction to occur. The energy absorbed is often heat energy or electrical energy. Adding electrical energy to metal oxides can separate them into the pure metal and oxygen. Adding electrical energy to sodium chloride can cause the table salt to break into its original sodium and chlorine parts.

Exothermic Reactions

Chemical reactions in which energy is released are exothermic. The energy that is released was originally stored in the chemical bonds of the reactants. Often the heat given off causes the product(s) to feel hot. Any reaction that involves combustion (burning) is an exothermic chemical reaction.

Answer 2

I have that exact same question for homework. The answer is synthesis, decomposition, and replacement. Hope that helps!

Answer 3

Synthesis is the combination of two elements. For example, school + bus = schoolbus

Answer 4

Three types of chemical reactions can be classified as synthesis, decomposition, &&&& replacement. :]