Question

section b: you may draw arrows to help you if you want but it is not required. write the names of the elements in the order they appear in the formula from left to right. if the element appears more than once, only write it once, then add its atoms together.

1. 3na₂so₄ # of molecules: __ # of elements: name of element: # of atoms: total # of atoms: the #3 is a __ (coefficient or subscript)
2. 2znso₄ # of molecules: __ # of elements: name of element: # of atoms: total # of atoms: the #4 is a __ (coefficient or subscript)
3. k₂co₃ # of molecules: __ # of elements: name of element: # of atoms: total # of atoms: the #3 is a __ (coefficient or subscript)
4. ba₃(po₄)₂ # of molecules: __ # of elements: name of element: # of atoms: total # of atoms: the #3 is a __ (coefficient or subscript)
5. na₂cro₄ # of molecules: __ # of elements: name of element: # of atoms: total # of atoms: the #4 is a __ (coefficient or subscript)
6. 4al₂(co₃)₃ # of molecules: __ # of elements: name of element: # of atoms: total # of atoms: the assumed 1 is a __ (coefficient or subscript)

Explanation:

Step1: Analyze 3Na₂SO₄

The coefficient 3 indicates 3 molecules. There are 3 elements (sodium - Na, sulfur - S, oxygen - O). Sodium has 2×3 = 6 atoms, sulfur has 1×3 = 3 atoms, oxygen has 4×3 = 12 atoms. Total atoms are 6 + 3+12 = 21. The 3 is a coefficient.

Step2: Analyze 2ZnSO₄

The coefficient 2 indicates 2 molecules. There are 3 elements (zinc - Zn, sulfur - S, oxygen - O). Zinc has 1×2 = 2 atoms, sulfur has 1×2 = 2 atoms, oxygen has 4×2 = 8 atoms. Total atoms are 2 + 2+8 = 12. The 4 is a sub - script.

Step3: Analyze K₂CO₃

There is 1 molecule. There are 3 elements (potassium - K, carbon - C, oxygen - O). Potassium has 2 atoms, carbon has 1 atom, oxygen has 3 atoms. Total atoms are 2 + 1+3 = 6. The 3 is a sub - script.

Step4: Analyze Ba₃(PO₄)₂

There is 1 molecule. There are 3 elements (barium - Ba, phosphorus - P, oxygen - O). Barium has 3 atoms, phosphorus has 1×2 = 2 atoms, oxygen has 4×2 = 8 atoms. Total atoms are 3 + 2+8 = 13. The 3 is a sub - script.

Step5: Analyze Na₂CrO₄

There is 1 molecule. There are 3 elements (sodium - Na, chromium - Cr, oxygen - O). Sodium has 2 atoms, chromium has 1 atom, oxygen has 4 atoms. Total atoms are 2 + 1+4 = 7. The 4 is a sub - script.

Step6: Analyze 4Al₂(CO₃)₃

The coefficient 4 indicates 4 molecules. There are 3 elements (aluminum - Al, carbon - C, oxygen - O). Aluminum has 2×4 = 8 atoms, carbon has 1×3×4 = 12 atoms, oxygen has 3×3×4 = 36 atoms. Total atoms are 8 + 12+36 = 56. The assumed 1 (not explicitly written but in CO₃) is a sub - script.

Answer:

1. 3Na₂SO₄:

• # of molecules: 3
• # of elements: 3
• Name of element: Sodium, Sulfur, Oxygen
• # of atoms: 6, 3, 12
• Total # of atoms: 21
• The 3 is a coefficient

1. 2ZnSO₄:

• # of molecules: 2
• # of elements: 3
• Name of element: Zinc, Sulfur, Oxygen
• # of atoms: 2, 2, 8
• Total # of atoms: 12
• The 4 is a sub - script

1. K₂CO₃:

• # of molecules: 1
• # of elements: 3
• Name of element: Potassium, Carbon, Oxygen
• # of atoms: 2, 1, 3
• Total # of atoms: 6
• The 3 is a sub - script

1. Ba₃(PO₄)₂:

• # of molecules: 1
• # of elements: 3
• Name of element: Barium, Phosphorus, Oxygen
• # of atoms: 3, 2, 8
• Total # of atoms: 13
• The 3 is a sub - script

1. Na₂CrO₄:

• # of molecules: 1
• # of elements: 3
• Name of element: Sodium, Chromium, Oxygen
• # of atoms: 2, 1, 4
• Total # of atoms: 7
• The 4 is a sub - script

1. 4Al₂(CO₃)₃:

• # of molecules: 4
• # of elements: 3
• Name of element: Aluminum, Carbon, Oxygen
• # of atoms: 8, 12, 36
• Total # of atoms: 56
• The assumed 1 is a sub - script