Question

1. choose the best answer.

when the following equation is balanced, what is the coefficient for libr?
__ f₂(g)+ libr(aq)→ lif(s)+__ br₂(l)
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1. choose the best answer.

when the following equation is balanced, what is the coefficient for k₂so₄?
__ albr₃+ k₂so₄→ kbr+__ al₂(so₄)₃
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Explanation:

Question 7

Step1: Balance Br atoms

On the right, there are 2 Br atoms (in $Br_2$), so we need 2 $LiBr$ to have 2 Br on the left.

Step2: Balance Li and F atoms

With 2 $LiBr$, we get 2 Li, so we need 2 $LiF$ (to balance Li). Then, for F, 2 $LiF$ has 2 F, so we need 1 $F_2$ (since $F_2$ has 2 F atoms). Now check: $F_2 + 2LiBr
ightarrow 2LiF + Br_2$. All atoms are balanced.

Step1: Balance Al atoms

On the right, there are 2 Al atoms (in $Al_2(SO_4)_3$), so we need 2 $AlBr_3$ to have 2 Al on the left.

Step2: Balance Br atoms

2 $AlBr_3$ has 6 Br atoms, so we need 6 $KBr$ (to balance Br).

Step3: Balance K atoms

6 $KBr$ has 6 K atoms, so we need 3 $K_2SO_4$ (since each $K_2SO_4$ has 2 K, 3×2 = 6 K).

Step4: Balance $SO_4^{2-}$ ions

3 $K_2SO_4$ has 3 $SO_4^{2-}$ ions, and $Al_2(SO_4)_3$ has 3 $SO_4^{2-}$ ions, so that's balanced. The equation is $2AlBr_3 + 3K_2SO_4
ightarrow 6KBr + Al_2(SO_4)_3$.

Answer:

2 (the coefficient for $LiBr$ is 2)

Question 8