Synthesis reactions involve the combination of simple elements to create a complex compound.
The general formula is:
X + Y → XY
or
element + element → compound
This is analogous to a man and a woman forming a relationship.
Some lone elements are “special” and will be found as diatomics or polyatomics: H2, O2, N2, F2, Cl2, Br2, I2, P4, S8.
All other elements are monatomics: Fe, Ca, Li, etc.
Remember: Elements combined in compounds use their valences to determine the ratios in a compound.
Practice Questions:
For each of the following (a) complete the word equation, (b) create a balanced equation.
(a) hydrogen + oxygen →
(b) sodium + chlorine →
(c) lithium + fluorine →
Answers:
(a) hydrogen + oxygen → hydrogen oxide
2H2 + O2 → 2H2O
(b) sodium + chlorine → sodium chloride
2Na + Cl2 → 2NaCl
(c) lithium + fluorine → lithium fluoride
2Li + F2 → 2LiF
Homework:
Do the "Synthesis Reactions" at the top of the page.
Answers:
