Question

4 cocl₆

1. identify the coefficient above
2. identify the subscript above

balance the following:

1. beo + hcl → becl₂ + h₂o
2. ag + cl₂ → agcl
3. ag₂s → ag + s₈

Explanation:

Step1: Identify coefficient and sub - script

In the formula $4CoCl_{6}$, the coefficient is the number in front of the chemical formula, which is 4. The sub - script is the number following the element symbol, for Cl it is 6.

Step2: Balance $BeO + HCl

ightarrow BeCl_{2}+H_{2}O$
Count the number of atoms on both sides. For Be, there is 1 on both sides initially. For O, there is 1 on the left. For H and Cl, on the left we have 1 H and 1 Cl, and on the right 2 Cl and 2 H in $BeCl_{2}$ and $H_{2}O$. We need 2 moles of HCl to balance the equation. So the balanced equation is $BeO + 2HCl
ightarrow BeCl_{2}+H_{2}O$.

Step3: Balance $Ag + Cl_{2}

ightarrow AgCl$
There are 2 Cl atoms on the left and 1 Cl atom on the right. We need 2 moles of AgCl and 2 moles of Ag to balance the equation. So it is $2Ag+Cl_{2}
ightarrow 2AgCl$.

Step4: Balance $Ag_{2}S

ightarrow Ag + S_{8}$
There are 8 S atoms in $S_{8}$. We need 8 moles of $Ag_{2}S$ to get 8 S atoms on the left. Then we have 16 moles of Ag on the left, so we need 16 moles of Ag on the right. The balanced equation is $8Ag_{2}S
ightarrow 16Ag + S_{8}$.

Answer:

1. 4
2. 6
3. 1, 2, 1, 1
4. 2, 1, 2
5. 8, 16, 1