Question

what type of chemical reaction is shown:
$2\\ al + cr_2o_3 \
ightarrow 2\\ cr + al_2o_3$
decompostion
single replacement
double replacement
synthesis

Explanation:

In the reaction $2\text{Al} + \text{Cr}_2\text{O}_3
ightarrow 2\text{Cr} + \text{Al}_2\text{O}_3$, the free element aluminum (Al) replaces chromium (Cr) in its compound $\text{Cr}_2\text{O}_3$, which matches the definition of a single replacement reaction (one element replaces another in a compound).

Answer:

B. Single Replacement