Question

silicon, the second most common element in earths crust, is commonly used in semiconductors and electronics such as computers. since it is naturally found in quartz, it is necessary to heat the quartz with carbon to separate the silicon. the chemical equation is
sio₂ + 2c → si + 2co

which chemical formula(s) represents the reactants? | which chemical formula(s) represents the products?

how many of each atom is present in the reactants? | how many of each atom is present in the products?
si | o | c | si | o | c

is this a balanced equation (yes or no)? explain why

extra practice 8 - 10 are the equations below balanced?

1. na + h₂o → naoh + h₂
2. fe + o₂ → fe₂o₃
3. al + o₂ → al₂o₃

Explanation:

Part 1: Analyzing the reaction \( \boldsymbol{SiO_2 + 2C

ightarrow Si + 2CO} \)

1. Reactants and Products

• Reactants: Substances on the left of the arrow. So \( SiO_2 \) (silicon dioxide) and \( C \) (carbon).
• Products: Substances on the right of the arrow. So \( Si \) (silicon) and \( CO \) (carbon monoxide).

2. Number of Atoms in Reactants

• For \( Si \): In \( SiO_2 \), there is 1 \( Si \) atom.
• For \( O \): In \( SiO_2 \), there are \( 2 \) \( O \) atoms.
• For \( C \): The coefficient is \( 2 \) (from \( 2C \)), so \( 2 \) \( C \) atoms.

3. Number of Atoms in Products

• For \( Si \): In \( Si \), there is \( 1 \) \( Si \) atom.
• For \( O \): In \( 2CO \), each \( CO \) has \( 1 \) \( O \), so \( 2 \times 1 = 2 \) \( O \) atoms.
• For \( C \): In \( 2CO \), each \( CO \) has \( 1 \) \( C \), so \( 2 \times 1 = 2 \) \( C \) atoms.

4. Is the Equation Balanced?

A balanced equation has equal numbers of each atom on both sides.

• \( Si \): \( 1 \) (reactants) = \( 1 \) (products)
• \( O \): \( 2 \) (reactants) = \( 2 \) (products)
• \( C \): \( 2 \) (reactants) = \( 2 \) (products)

Thus, the equation is balanced (yes), because the number of each atom is the same in reactants and products.

Part 2: Extra Practice (Balancing Check)

8. \( \boldsymbol{Na + H_2O

ightarrow NaOH + H_2} \)

• Reactants: \( Na \): 1, \( H \): 2, \( O \): 1
• Products: \( Na \): 1, \( H \): \( 1 + 2 = 3 \), \( O \): 1
• \( H \) atoms are unequal. Not balanced.

9. \( \boldsymbol{Fe + O_2

ightarrow Fe_2O_3} \)

• Reactants: \( Fe \): 1, \( O \): 2
• Products: \( Fe \): 2, \( O \): 3
• Both \( Fe \) and \( O \) are unequal. Not balanced.

10. \( \boldsymbol{Al + O_2

ightarrow Al_2O_3} \)

• Reactants: \( Al \): 1, \( O \): 2
• Products: \( Al \): 2, \( O \): 3
• Both \( Al \) and \( O \) are unequal. Not balanced.

Summary (for the main reaction \( SiO_2 + 2C

ightarrow Si + 2CO \)):

• Reactants: \( SiO_2, C \); Products: \( Si, CO \)
• Atoms in reactants: \( Si: 1, O: 2, C: 2 \)
• Atoms in products: \( Si: 1, O: 2, C: 2 \)
• Balanced: Yes (equal atoms on both sides).

Extra Practice Answers:

1. Not balanced
2. Not balanced
3. Not balanced

Answer:

Part 1: Analyzing the reaction \( \boldsymbol{SiO_2 + 2C

ightarrow Si + 2CO} \)

1. Reactants and Products

• Reactants: Substances on the left of the arrow. So \( SiO_2 \) (silicon dioxide) and \( C \) (carbon).
• Products: Substances on the right of the arrow. So \( Si \) (silicon) and \( CO \) (carbon monoxide).

2. Number of Atoms in Reactants

• For \( Si \): In \( SiO_2 \), there is 1 \( Si \) atom.
• For \( O \): In \( SiO_2 \), there are \( 2 \) \( O \) atoms.
• For \( C \): The coefficient is \( 2 \) (from \( 2C \)), so \( 2 \) \( C \) atoms.

3. Number of Atoms in Products

• For \( Si \): In \( Si \), there is \( 1 \) \( Si \) atom.
• For \( O \): In \( 2CO \), each \( CO \) has \( 1 \) \( O \), so \( 2 \times 1 = 2 \) \( O \) atoms.
• For \( C \): In \( 2CO \), each \( CO \) has \( 1 \) \( C \), so \( 2 \times 1 = 2 \) \( C \) atoms.

4. Is the Equation Balanced?

A balanced equation has equal numbers of each atom on both sides.

• \( Si \): \( 1 \) (reactants) = \( 1 \) (products)
• \( O \): \( 2 \) (reactants) = \( 2 \) (products)
• \( C \): \( 2 \) (reactants) = \( 2 \) (products)

Thus, the equation is balanced (yes), because the number of each atom is the same in reactants and products.

Part 2: Extra Practice (Balancing Check)

8. \( \boldsymbol{Na + H_2O

ightarrow NaOH + H_2} \)

• Reactants: \( Na \): 1, \( H \): 2, \( O \): 1
• Products: \( Na \): 1, \( H \): \( 1 + 2 = 3 \), \( O \): 1
• \( H \) atoms are unequal. Not balanced.

9. \( \boldsymbol{Fe + O_2

ightarrow Fe_2O_3} \)

• Reactants: \( Fe \): 1, \( O \): 2
• Products: \( Fe \): 2, \( O \): 3
• Both \( Fe \) and \( O \) are unequal. Not balanced.

10. \( \boldsymbol{Al + O_2

ightarrow Al_2O_3} \)

• Reactants: \( Al \): 1, \( O \): 2
• Products: \( Al \): 2, \( O \): 3
• Both \( Al \) and \( O \) are unequal. Not balanced.

Summary (for the main reaction \( SiO_2 + 2C

ightarrow Si + 2CO \)):

• Reactants: \( SiO_2, C \); Products: \( Si, CO \)
• Atoms in reactants: \( Si: 1, O: 2, C: 2 \)
• Atoms in products: \( Si: 1, O: 2, C: 2 \)
• Balanced: Yes (equal atoms on both sides).

Extra Practice Answers:

1. Not balanced
2. Not balanced
3. Not balanced