First question
[tex]Pb(NO_3)_2 + KI \rightarrow PbI_2 + KNO_3[/tex]
Balaneced:
[tex]Pb(NO_3)_2 + 2KI \rightarrow PbI_2 + 2KNO_3[/tex]
Find how many moles potassium iodide it is in 345.0 grams
[tex]n_{KI} = \frac{345.0 \ g}{166.0 \ g/mol} = 2.078 \ mole[/tex]
Find how many moles potassium nitrate there is for 2.078 moles [tex]KI[/tex]
[tex]n_{KNO_3} = \frac{2}{2} \cdot n_{KI} = 2.078 \ mole[/tex]
Find how many grams potassium nitrate there is in 2.078 moles [tex]KNO_3[/tex]
[tex]m_{KNO_3} = 2.078 \ mol \cdot 101.1 \ g/mol = 210.1 \ g[/tex]
Second question
[tex]yield \ \% = \frac{experimental}{theoretical} \cdot 100 = \frac{195.3 \ grams}{210.1 \ grams} \cdot 100 = 93.0 \ \%[/tex]
