Answer: a)
: Decomposition
b)
: double displacement
c)
: Synthesis (Combination)
d)
: redox
Explanation:
Decomposition is a type of chemical reaction in which one reactant gives two or more than two products.

A double displacement reaction is one in which exchange of ions take place.

Synthesis reaction is a chemical reaction in which two reactants are combining to form one product.

Redox reaction is a type of chemical reaction in which oxidation and reduction takes place in one single reaction. The oxidation number of one element increases and the oxidation number of other element decreases.

Answer:
20 mole of oxygen
Explanation:
1 mole of proprane reacts with 5 moles of oxygen so 4 time 5 equals 20
Chemical reactions can be identified when there is a change in color, energy is produced, change in odor, or if new substance forms.