## Chemistry: The Central Science (13th Edition)

$2Al(s)+3Cl_2(g)\rightarrow 2AlCl_3(s)$ This is combination.
$Al(s)+Cl_2(g)\rightarrow AlCl_3(s)$ This is a combination reaction because two elements are combining to form a new compound. $Cl$ is even on the left and odd on the right. Use a coefficient of 2 on $AlCl_3$ to make the count even to enable balancing. $Al(s)+Cl_2(g)\rightarrow 2AlCl_3(s)$ Use a coefficient of 2 on $Al$ to balance $Al$. Use a coefficient of 3 on $Cl$ to balance $Cl$. $2Al(s)+3Cl_2(g)\rightarrow 2AlCl_3(s)$