Question

1. pb(no₃)₂ # of molecules: # of elements: name of element # of atoms: total # of atoms: the #3 is a (coefficient or subscript) 12) 4au(io₃)₃ # of molecules: # of elements: name of element: # of atoms: total # of atoms: the #4 is a (coefficient or subscript) 13) co₂ # of molecules: # of elements: name of element: # of atoms: total # of atoms: the #2 is a (coefficient or subscript) 14) 3cacl₂ # of molecules: # of elements: name of element: # of atoms: total # of atoms: the #3 is a (coefficient or subscript) 15) cr(nh₃)₄(no₃)₂ # of molecules: # of elements: name of element: # of atoms: total # of atoms: the #6 is a (coefficient or subscript) 16) 5al(c₂h₃o₂)₃ # of molecules: # of elements: name of element: # of atoms: total # of atoms: the #2 is a (coefficient or subscript)

Explanation:

Step1: Analyze $Pb(NO_3)_2$

• # of molecules: 1
• # of elements: 3 (lead - Pb, nitrogen - N, oxygen - O)
• Pb: 1 atom, N: 2 atoms, O: 6 atoms
• Total # of atoms: 1 + 2+6 = 9
• The 3 is a subscript

Step2: Analyze $4Au(IO_3)_3$

• # of molecules: 4
• # of elements: 3 (gold - Au, iodine - I, oxygen - O)
• Au: 4 atoms, I: 12 atoms, O: 36 atoms
• Total # of atoms: 4+12 + 36=52
• The 4 is a coefficient

Step3: Analyze $CO_2$

• # of molecules: 1
• # of elements: 2 (carbon - C, oxygen - O)
• C: 1 atom, O: 2 atoms
• Total # of atoms: 1+2 = 3
• The 2 is a subscript

Step4: Analyze $3CaCl_2$

• # of molecules: 3
• # of elements: 2 (calcium - Ca, chlorine - Cl)
• Ca: 3 atoms, Cl: 6 atoms
• Total # of atoms: 3+6 = 9
• The 3 is a coefficient

Step5: Analyze $Cr(NH_3)_6(NO_3)_3$

• # of molecules: 1
• # of elements: 4 (chromium - Cr, nitrogen - N, hydrogen - H, oxygen - O)
• Cr: 1 atom, N: 9 atoms, H: 18 atoms, O: 9 atoms
• Total # of atoms: 1+9+18 + 9=37
• The 6 is a subscript

Step6: Analyze $5Al(C_2H_3O_2)_3$

• # of molecules: 5
• # of elements: 4 (aluminum - Al, carbon - C, hydrogen - H, oxygen - O)
• Al: 5 atoms, C: 30 atoms, H: 45 atoms, O: 30 atoms
• Total # of atoms: 5+30+45+30 = 110
• The 2 is a subscript

Answer:

11)

• # of molecules: 1
• # of elements: 3
• Name of element: Pb, N, O
• # of atoms: 1, 2, 6
• Total # of atoms: 9
• The 3 is a subscript

12)

• # of molecules: 4
• # of elements: 3
• Name of element: Au, I, O
• # of atoms: 4, 12, 36
• Total # of atoms: 52
• The 4 is a coefficient

13)

• # of molecules: 1
• # of elements: 2
• Name of element: C, O
• # of atoms: 1, 2
• Total # of atoms: 3
• The 2 is a subscript

14)

• # of molecules: 3
• # of elements: 2
• Name of element: Ca, Cl
• # of atoms: 3, 6
• Total # of atoms: 9
• The 3 is a coefficient

15)

• # of molecules: 1
• # of elements: 4
• Name of element: Cr, N, H, O
• # of atoms: 1, 9, 18, 9
• Total # of atoms: 37
• The 6 is a subscript

16)

• # of molecules: 5
• # of elements: 4
• Name of element: Al, C, H, O
• # of atoms: 5, 30, 45, 30
• Total # of atoms: 110
• The 2 is a subscript