Question

which set of coefficients correctly balances the following reaction?
s₈(s) + p₄(s) → __ p₄s₃(s)
a. 8, 3, 8
b. 3, 8, 8
c. 6, 8, 4
d. 1, 1, 1
select one:
a
b
c
d

Explanation:

Step1: Balance sulfur atoms

Let the coefficients be $a$, $b$, $c$ for $\text{S}_8$, $\text{P}_4$, $\text{P}_4\text{S}_3$ respectively.
Sulfur balance: $8a = 3c$ → $c=\frac{8a}{3}$

Step2: Balance phosphorus atoms

Phosphorus balance: $4b = 4c$ → $b=c$

Step3: Choose smallest integer $a$

To get integer coefficients, set $a=3$. Then $c=\frac{8\times3}{3}=8$, so $b=8$.

Step4: Verify balanced equation

Substitute: $3\text{S}_8 + 8\text{P}_4
ightarrow 8\text{P}_4\text{S}_3$
Check S: $3\times8=24$; $8\times3=24$
Check P: $8\times4=32$; $8\times4=32$

Answer:

B. 3, 8, 8