Question

what is the correct coefficient ratio to have the equation balanced?

pb(no₃)₂ + ki → kno₃ + pbi₂

○ 1:2:2:1
○ 1:2:1:2
○ 2:1:1:2
○ 1:1:1:1

Explanation:

Step1: Balance iodine atoms

On the right - hand side, there are 2 iodine atoms in \(PbI_2\). On the left - hand side, there is 1 iodine atom in \(KI\). So, we put a coefficient of 2 in front of \(KI\). The equation becomes \(Pb(NO_3)_2+2KI
ightarrow KNO_3 + PbI_2\).

Step2: Balance potassium and nitrate atoms

After putting a coefficient of 2 in front of \(KI\), we have 2 potassium atoms on the left. On the right - hand side, in \(KNO_3\), we need to balance potassium. Also, for nitrate \((NO_3)\) groups: there are 2 \(NO_3\) groups on the left (\(Pb(NO_3)_2\)) and 1 on the right (\(KNO_3\)). By putting a coefficient of 2 in front of \(KNO_3\), the equation \(Pb(NO_3)_2 + 2KI=2KNO_3+PbI_2\) is balanced.

The coefficients of \(Pb(NO_3)_2\), \(KI\), \(KNO_3\), \(PbI_2\) are 1, 2, 2, 1 respectively.

Answer:

1:2:2:1