Question

writing and balancing chemical equations
quiz complete
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this formula equation is unbalanced.
$p_4(s) + 6cl_2(g) \
ightarrow pcl_3(l)$
which coefficient should be placed in front of $pcl_3$ to balance this equation?
1
2
4
6

Explanation:

get 4 P atoms, multiply $\text{PCl}_5$ by 4: $4\text{PCl}_5$ (now 4 P atoms).

Step3: Check Cl atom balance

Left side: $6\text{Cl}_2$ has $6\times2=12$ Cl atoms.
Right side: $4\text{PCl}_5$ has $4\times5=20$ Cl atoms. Wait, adjust left Cl: to get 20 Cl, $\text{Cl}_2$ needs 10 molecules, but the question only asks for $\text{PCl}_5$ coefficient. The P balance first requires 4, and that is the correct coefficient for $\text{PCl}_5$ to balance P, and the full balanced equation is $\text{P}_4(s) + 10\text{Cl}_2(g)
ightarrow 4\text{PCl}_5(l)$. The question only asks for the $\text{PCl}_5$ coefficient, which is 4.

Answer:

get 4 P atoms, multiply $\text{PCl}_5$ by 4: $4\text{PCl}_5$ (now 4 P atoms).

Step3: Check Cl atom balance

Left side: $6\text{Cl}_2$ has $6\times2=12$ Cl atoms.
Right side: $4\text{PCl}_5$ has $4\times5=20$ Cl atoms. Wait, adjust left Cl: to get 20 Cl, $\text{Cl}_2$ needs 10 molecules, but the question only asks for $\text{PCl}_5$ coefficient. The P balance first requires 4, and that is the correct coefficient for $\text{PCl}_5$ to balance P, and the full balanced equation is $\text{P}_4(s) + 10\text{Cl}_2(g)
ightarrow 4\text{PCl}_5(l)$. The question only asks for the $\text{PCl}_5$ coefficient, which is 4.