Question

1. __ c + h₂ → __ ch₄

elements | reactants | products
c | |
h | |

1. __ sr + o₂ → __ sro

elements | reactants | products
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1. __ k + o₂ → __ k₂o

elements | reactants | products
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1. __ mg + cl₂ → __ mgcl₂

elements | reactants | products
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1. __ rb + i₂ → __ rbi

elements | reactants | products
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1. __ beo + h₂o → __ be(oh)₂

elements | reactants | products
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1. __ na₂o + h₂o → __ naoh

elements | reactants | products
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1. __ so₃ + h₂o → __ h₂so₄

elements | reactants | products
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Explanation:

Step1: Balance Equation 8

For the reaction \( \text{C} + \text{H}_2 ightarrow \text{CH}_4 \):
- **C atoms**: Reactants have 1 C, products have 1 C (balanced for C).
- **H atoms**: Reactants have \( 2x \) (where \( x \) is coefficient of \( \text{H}_2 \)), products have 4 H. So \( 2x = 4 \Rightarrow x = 2 \). But wait, product \( \text{CH}_4 \) has 1 C, so coefficient of C is 1, \( \text{H}_2 \) is 2, and \( \text{CH}_4 \) is 1? Wait no, let's redo:
- Let coefficients be \( a\text{C} + b\text{H}_2 ightarrow c\text{CH}_4 \).
- C: \( a = c \)
- H: \( 2b = 4c \)
- Let \( c = 1 \), then \( a = 1 \), \( 2b = 4(1) \Rightarrow b = 2 \)? No, wait \( \text{CH}_4 \) has 4 H, so \( 2b = 4c \). If \( c = 1 \), \( b = 2 \), but then reactants: 1 C, 4 H; products: 1 C, 4 H. Wait no, \( \text{H}_2 \) is diatomic, so \( b\text{H}_2 \) has \( 2b \) H. Products \( c\text{CH}_4 \) has \( 4c \) H. So \( 2b = 4c \Rightarrow b = 2c \). Let \( c = 1 \), then \( b = 2 \), \( a = 1 \). So equation: \( 1\text{C} + 2\text{H}_2 ightarrow 1\text{CH}_4 \)? Wait no, that would be \( \text{C} + 2\text{H}_2 ightarrow \text{CH}_4 \), but let's check H: 2*2=4, products 4 H. C: 1=1. Yes. Now fill the table:
- Elements: C, H
- C: Reactants (1), Products (1)
- H: Reactants (2*2=4? Wait no, \( \text{H}_2 \) coefficient is 2, so H atoms in reactants: 2*2=4? Wait no, \( \text{H}_2 \) has 2 H per molecule, so coefficient 2 means 2*2=4 H. Products: \( \text{CH}_4 \) has 4 H. So table:
- C: Reactants (1), Products (1)
- H: Reactants (4), Products (4)

Step2: Balance Equation 9 (\( \text{Sr} + \text{O}_2

ightarrow \text{SrO} \))
- Let coefficients be \( a\text{Sr} + b\text{O}_2 ightarrow c\text{SrO} \).
- Sr: \( a = c \)
- O: \( 2b = c \)
- Let \( c = 2 \), then \( a = 2 \), \( 2b = 2 \Rightarrow b = 1 \). So equation: \( 2\text{Sr} + 1\text{O}_2 ightarrow 2\text{SrO} \).
- Table:
- Elements: Sr, O
- Sr: Reactants (2), Products (2)
- O: Reactants (2*1=2), Products (2*1=2)

Step3: Balance Equation 10 (\( \text{K} + \text{O}_2

ightarrow \text{K}_2\text{O} \))
- Coefficients: \( a\text{K} + b\text{O}_2 ightarrow c\text{K}_2\text{O} \)
- K: \( a = 2c \)
- O: \( 2b = c \)
- Let \( c = 2 \), then \( a = 4 \), \( 2b = 2 \Rightarrow b = 1 \). Wait, \( \text{K}_2\text{O} \) has 1 O per molecule, so \( c\text{K}_2\text{O} \) has \( c \) O. Reactants \( b\text{O}_2 \) has \( 2b \) O. So \( 2b = c \). Let \( c = 2 \), \( b = 1 \), \( a = 4 \). Equation: \( 4\text{K} + 1\text{O}_2 ightarrow 2\text{K}_2\text{O} \).
- Table:
- Elements: K, O
- K: Reactants (4), Products (4)
- O: Reactants (2), Products (2)

Step4: Balance Equation 11 (\( \text{Mg} + \text{Cl}_2

ightarrow \text{MgCl}_2 \))
- Coefficients: \( a\text{Mg} + b\text{Cl}_2 ightarrow c\text{MgCl}_2 \)
- Mg: \( a = c \)
- Cl: \( 2b = 2c \Rightarrow b = c \)
- Let \( c = 1 \), then \( a = 1 \), \( b = 1 \). Equation: \( 1\text{Mg} + 1\text{Cl}_2 ightarrow 1\text{MgCl}_2 \).
- Table:
- Elements: Mg, Cl
- Mg: Reactants (1), Products (1)
- Cl: Reactants (2), Products (2)

Step5: Balance Equation 12 (\( \text{Rb} + \text{I}_2

ightarrow \text{RbI} \))
- Coefficients: \( a\text{Rb} + b\text{I}_2 ightarrow c\text{RbI} \)
- Rb: \( a = c \)
- I: \( 2b = c \)
- Let \( c = 2 \), then \( a = 2 \), \( 2b = 2 \Rightarrow b = 1 \). Equation: \( 2\text{Rb} + 1\text{I}_2 ightarrow 2\text{RbI} \).
- Table:
- Elements: Rb, I
- Rb: Reactants (2), Products (2)
- I: Reactants (2), Products (2)

Step6: Balance Equation 13 (\( \text{BeO} + \text{H}_2\text{O}

ightarrow \text{Be(OH)}_2 \))
- Coefficients: \( a\text{BeO} + b\text{H}_2\text{O} ightarrow c\text{Be(OH)}_2 \)
- Be: \( a = c \)
- O: \( a + b = 2c \) (BeO has 1 O, \( \text{H}_2\text{O} \) has 1 O, \( \text{Be(OH)}_2 \) has 2 O)
- H: \( 2b = 2c \Rightarrow b = c \)
- Let \( c = 1 \), then \( a = 1 \), \( b = 1 \). Check O: \( 1 + 1 = 2(1) \Rightarrow 2 = 2 \). Equation: \( 1\text{BeO} + 1\text{H}_2\text{O} ightarrow 1\text{Be(OH)}_2 \).
- Table:
- Elements: Be, O, H
- Be: Reactants (1), Products (1)
- O: Reactants (1 + 1 = 2), Products (2)
- H: Reactants (2), Products (2)

Step7: Balance Equation 14 (\( \text{Na}_2\text{O} + \text{H}_2\text{O}

ightarrow \text{NaOH} \))
- Coefficients: \( a\text{Na}_2\text{O} + b\text{H}_2\text{O} ightarrow c\text{NaOH} \)
- Na: \( 2a = c \)
- O: \( a + b = c \)
- H: \( 2b = c \)
- Let \( c = 2 \), then \( 2a = 2 \Rightarrow a = 1 \), \( 2b = 2 \Rightarrow b = 1 \). Check O: \( 1 + 1 = 2 \Rightarrow 2 = 2 \). Equation: \( 1\text{Na}_2\text{O} + 1\text{H}_2\text{O} ightarrow 2\text{NaOH} \).
- Table:
- Elements: Na, O, H
- Na: Reactants (2), Products (2)
- O: Reactants (1 + 1 = 2), Products (2)
- H: Reactants (2), Products (2)

Step8: Balance Equation 15 (\( \text{SO}_3 + \text{H}_2\text{O}

ightarrow \text{H}_2\text{SO}_4 \))
- Coefficients: \( a\text{SO}_3 + b\text{H}_2\text{O} ightarrow c\text{H}_2\text{SO}_4 \)
- S: \( a = c \)
- O: \( 3a + b = 4c \)
- H: \( 2b = 2c \Rightarrow b = c \)
- Let \( c = 1 \), then \( a = 1 \), \( b = 1 \). Check O: \( 3(1) + 1 = 4(1) \Rightarrow 4 = 4 \). Equation: \( 1\text{SO}_3 + 1\text{H}_2\text{O} ightarrow 1\text{H}_2\text{SO}_4 \).
- Table:
- Elements: S, O, H
- S: Reactants (1), Products (1)
- O: Reactants (3 + 1 = 4), Products (4)
- H: Reactants (2), Products (2)

Answer (for each equation, balanced coefficients and table filled):

Equation 8:

- Coefficients: \( \boldsymbol{1}\text{C} + \boldsymbol{2}\text{H}_2 ightarrow \boldsymbol{1}\text{CH}_4 \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| C | 1 | 1 |
| H | 4 (2×2) | 4 |

Equation 9:

- Coefficients: \( \boldsymbol{2}\text{Sr} + \boldsymbol{1}\text{O}_2 ightarrow \boldsymbol{2}\text{SrO} \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| Sr | 2 | 2 |
| O | 2 | 2 |

Equation 10:

- Coefficients: \( \boldsymbol{4}\text{K} + \boldsymbol{1}\text{O}_2 ightarrow \boldsymbol{2}\text{K}_2\text{O} \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| K | 4 | 4 |
| O | 2 | 2 |

Equation 11:

- Coefficients: \( \boldsymbol{1}\text{Mg} + \boldsymbol{1}\text{Cl}_2 ightarrow \boldsymbol{1}\text{MgCl}_2 \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| Mg | 1 | 1 |
| Cl | 2 | 2 |

Equation 12:

- Coefficients: \( \boldsymbol{2}\text{Rb} + \boldsymbol{1}\text{I}_2 ightarrow \boldsymbol{2}\text{RbI} \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| Rb | 2 | 2 |
| I | 2 | 2 |

Equation 13:

- Coefficients: \( \boldsymbol{1}\text{BeO} + \boldsymbol{1}\text{H}_2\text{O} ightarrow \boldsymbol{1}\text{Be(OH)}_2 \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| Be | 1 | 1 |
| O | 2 | 2 |
| H | 2 | 2 |

Equation 14:

- Coefficients: \( \boldsymbol{1}\text{Na}_2\text{O} + \boldsymbol{1}\text{H}_2\text{O} ightarrow \boldsymbol{2}\text{NaOH} \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| Na | 2 | 2 |
| O | 2 | 2 |
| H | 2 | 2 |

Equation 15:

- Coefficients: \( \boldsymbol{1}\text{SO}_3 + \boldsymbol{1}\text{H}_2\text{O} ightarrow \boldsymbol{1}\text{H}_2\text{SO}_4 \)
- Table:
| Elements | Reactants | Products |
|----------|-----------|----------|
| S | 1 | 1 |
| O | 4 | 4 |
| H | 2 | 2 |

Answer:

(for each equation, balanced coefficients and table filled):

Equation 8:

• Coefficients: \( \boldsymbol{1}\text{C} + \boldsymbol{2}\text{H}_2

ightarrow \boldsymbol{1}\text{CH}_4 \)

• Table:

Elements	Reactants	Products
H	4 (2×2)	4

Equation 9:

• Coefficients: \( \boldsymbol{2}\text{Sr} + \boldsymbol{1}\text{O}_2

ightarrow \boldsymbol{2}\text{SrO} \)

• Table:

Elements	Reactants	Products
O	2	2

Equation 10:

• Coefficients: \( \boldsymbol{4}\text{K} + \boldsymbol{1}\text{O}_2

ightarrow \boldsymbol{2}\text{K}_2\text{O} \)

• Table:

Elements	Reactants	Products
O	2	2

Equation 11:

• Coefficients: \( \boldsymbol{1}\text{Mg} + \boldsymbol{1}\text{Cl}_2

ightarrow \boldsymbol{1}\text{MgCl}_2 \)

• Table:

Elements	Reactants	Products
Cl	2	2

Equation 12:

• Coefficients: \( \boldsymbol{2}\text{Rb} + \boldsymbol{1}\text{I}_2

ightarrow \boldsymbol{2}\text{RbI} \)

• Table:

Elements	Reactants	Products
I	2	2

Equation 13:

• Coefficients: \( \boldsymbol{1}\text{BeO} + \boldsymbol{1}\text{H}_2\text{O}

ightarrow \boldsymbol{1}\text{Be(OH)}_2 \)

• Table:

Elements	Reactants	Products
O	2	2
H	2	2

Equation 14:

• Coefficients: \( \boldsymbol{1}\text{Na}_2\text{O} + \boldsymbol{1}\text{H}_2\text{O}

ightarrow \boldsymbol{2}\text{NaOH} \)

• Table:

Elements	Reactants	Products
O	2	2
H	2	2

Equation 15:

• Coefficients: \( \boldsymbol{1}\text{SO}_3 + \boldsymbol{1}\text{H}_2\text{O}

ightarrow \boldsymbol{1}\text{H}_2\text{SO}_4 \)

• Table:

Elements	Reactants	Products
O	4	4
H	2	2