To determine which of the given chemical equations is correctly balanced, we need to ensure that the number of atoms of each element on the reactant side equals the number on the product side. Let's analyze each option step-by-step:
Option A: [tex]\( NaClO_3 \rightarrow NaCl + 3 O_2 \)[/tex]
- Reactants:
- Na: 1 atom
- Cl: 1 atom
- O: 3 atoms
- Products:
- Na: 1 atom
- Cl: 1 atom
- O: 6 atoms (because [tex]\(3 O_2\)[/tex] means [tex]\(3 \times 2\)[/tex] atoms of oxygen)
The oxygen atoms are not balanced (3 on the left, 6 on the right). Therefore, this equation is not balanced.
Option B: [tex]\( 2 HgO \rightarrow 2 Hg + O_2 \)[/tex]
- Reactants:
- Hg: 2 atoms
- O: 2 atoms (because [tex]\(2 HgO\)[/tex] means [tex]\(2 \times 1\)[/tex] atoms of oxygen)
- Products:
- Hg: 2 atoms
- O: 2 atoms (because [tex]\(O_2\)[/tex] means [tex]\(1 \times 2\)[/tex] atoms of oxygen)
Both mercury and oxygen atoms are balanced. Therefore, this equation is balanced.
Option C: [tex]\( 2 ZnS + O_2 \rightarrow 2 ZnO + 2 SO_2 \)[/tex]
- Reactants:
- Zn: 2 atoms
- S: 2 atoms
- O: 2 atoms
- Products:
- Zn: 2 atoms
- S: 2 atoms
- O: 6 atoms (because [tex]\(2 ZnO \rightarrow 2 \times 1 = 2\)[/tex] atoms and [tex]\(2 SO_2 \rightarrow 2 \times 2 = 4\)[/tex] atoms, total [tex]\(2 + 4 = 6\)[/tex] atoms of oxygen)
The oxygen atoms are not balanced (2 on the left, 6 on the right). Therefore, this equation is not balanced.
Option D: [tex]\( 4 CO + Fe_3O_4 \rightarrow 4 CO_2 + Fe \)[/tex]
- Reactants:
- C: 4 atoms
- O: 4 atoms (from CO) + 4 atoms (from Fe_3O_4) = 8 atoms
- Fe: 3 atoms
- Products:
- C: 4 atoms
- O: 8 atoms (from [tex]\(4 CO_2\rightarrow 4 \times 2\)[/tex])
- Fe: 1 atom
The iron atoms are not balanced (3 on the left, 1 on the right). Therefore, this equation is not balanced.
Option E: [tex]\( 2 Fe + 2 Cl_2 \rightarrow 2 FeCl_3 \)[/tex]
- Reactants:
- Fe: 2 atoms
- Cl: 4 atoms (because [tex]\(2 Cl_2 \rightarrow 2 \times 2\)[/tex])
- Products:
- Fe: 2 atoms
- Cl: 6 atoms (because [tex]\(2 FeCl_3 \rightarrow 2 \times 3\)[/tex])
The chlorine atoms are not balanced (4 on the left, 6 on the right). Therefore, this equation is not balanced.
After analyzing each option, the correctly balanced equation is Option B.
