Question

how do you know there was a chemical reaction?
check all indicators below.
✓ a solid precipitate formed.
✓ the color changed.
✗ a gas was produced.
✗ the reaction absorbed or released heat.
complete
fill in the blanks in the sentence below.
in the reaction at blood falls, iron and oxygen
combine to form iron oxide, which is called rust
(water is also present). the reactants are
✓ oxygen and iron , and the product is
✓ iron oxide.
complete
$4fe + 3o_{2} + xh_{2}o \
ightarrow 2fe_{2}o_{3} \cdot xh_{2}o$
the formation of rust (equation above) is an
example of both combustion and
synthesis.
decomposition.
single replacement.
double replacement.
done
3 of 5

Explanation:

A synthesis reaction is defined as a reaction where multiple reactants combine to form a single product. In the given rust formation equation, iron ($Fe$), oxygen ($O_2$), and water ($H_2O$) combine to form a single product, hydrated iron(III) oxide ($2Fe_2O_3 \cdot xH_2O$). Combustion here involves reaction with oxygen, and the reaction fits the synthesis reaction definition. Decomposition, single replacement, and double replacement reactions do not match the reactant-product structure here.

Answer:

synthesis.