Which of the following is the general equation for a synthesis reaction?

a. ab--a+b
b. a+b--ab
c. a+bc--b+ac
d. ab+cd--ad+bc

Answer is: B. A+B → AB.

Chemical synthesis is when a substance combines with another (in this example A and B) to form a new substance (AB).

Another example, synthesis of water from its elements: 2H₂ + O₂ → 2H₂O, nonpolar bonds between hydrogen and oxygen atoms are breaking and new polar bonds are forming between hydrogen and oxygen in molecule of water.

The general equation for the synthesis reaction is

Further Explanation:

The five types of chemical reactions are as follows:

1. Combination reactions:

These reactions are also known as synthesis reaction. These are the reaction in which two or more reactants combine to form single product. These are generally accompanied by the release of heat so they are exothermic reactions.

Examples of combination reactions are as follows:

(a)

(b)

2. Decomposition reactions:

The opposite of combination reactions is called as decomposition reaction. Here, a single reactant gets broken into two or more products. Such reactions are usually endothermic because energy is required to break the existing bonds between the reactant molecules.

Examples of decomposition reactions are as follows:

(a)

(b)

3. Displacement reactions

Also known as replacement or metathesis reactions. Here, one of the reactants gets replaced by the other one. Generally, the more reactive element displaces the less reactive element. Both metals and non-metals can take part in displacement reactions.

Examples of displacement reactions are as follows:

(a)

(b)

4. Double displacement reactions

These are the reaction in which ions of two compound interchange with each other to form the product. For example, the general double displacement reaction between two compound AX and BY is as follows:

Examples of double displacement reactions are as follows:

(a)

(b)

5. Combustion reactions:

These are the reactions that take place when hydrocarbons are burnt in presence of oxygen to form carbon dioxide and water. These are also referred to burning.  

Example of combustion reactions are as follows:

(a)

(b)

A) The given general reaction is,

Here, a single reactant AB is broken down to form A and B as two products. So it is a decomposition reaction.

B) The given general reaction is,

Here, two reactants, A and B combine to form a single product, AB. So it is a combination or synthesis reaction.

C) The given general reaction is,

Here, C is replaced from B by A. So it is a single displacement reaction.

D) The given general reaction is,

Here, B and C both are replaced from AB and CD respectively to form AD and BC are formed. So it is a double displacement reaction.

Learn more:

1. Balanced chemical equation:

2. Number of covalent bonds does nitrogen formed with its unpaired:

Answer details:

Grade: High School

Subject: Chemistry

Chapter: Chemical reaction and equation

Keywords: types of reactions, combination reaction, decomposition reaction, double displacement reaction, combustion reaction, A, B, AB, CD, BC, AD, synthesis, burning.