Which of the following contains the largest number of atoms -

Options

A. 11 g of `CO_(2)`
B. 4g of `H_(2)`
C. 5g of `NH_(3)`
D. 8g of `SO_(2)`

Answer

To determine which of the given options contains the largest number of atoms, we will calculate the number of atoms for each option step by step.

### Step 1: Calculate the number of atoms in 11 grams of CO2
1. **Find the molar mass of CO2:**
- Carbon (C) = 12 g/mol
- Oxygen (O) = 16 g/mol
- Molar mass of CO2 = 12 + (16 × 2) = 12 + 32 = 44 g/mol

2. **Calculate the number of moles of CO2:**
- Number of moles = Given weight / Molar mass = 11 g / 44 g/mol = 1/4 moles

3. **Calculate the number of atoms in CO2:**
- Each molecule of CO2 contains 3 atoms (1 C + 2 O).
- Number of atoms = Moles × Avogadro's number × 3 = (1/4) × NA × 3 = (3/4) × NA

### Step 2: Calculate the number of atoms in 4 grams of H2
1. **Find the molar mass of H2:**
- Hydrogen (H) = 1 g/mol
- Molar mass of H2 = 2 × 1 = 2 g/mol

2. **Calculate the number of moles of H2:**
- Number of moles = Given weight / Molar mass = 4 g / 2 g/mol = 2 moles

3. **Calculate the number of atoms in H2:**
- Each molecule of H2 contains 2 atoms.
- Number of atoms = Moles × Avogadro's number × 2 = 2 × NA × 2 = 4 × NA

### Step 3: Calculate the number of atoms in 5 grams of NH3
1. **Find the molar mass of NH3:**
- Nitrogen (N) = 14 g/mol
- Hydrogen (H) = 1 g/mol
- Molar mass of NH3 = 14 + (1 × 3) = 14 + 3 = 17 g/mol

2. **Calculate the number of moles of NH3:**
- Number of moles = Given weight / Molar mass = 5 g / 17 g/mol = 5/17 moles

3. **Calculate the number of atoms in NH3:**
- Each molecule of NH3 contains 4 atoms (1 N + 3 H).
- Number of atoms = Moles × Avogadro's number × 4 = (5/17) × NA × 4 = (20/17) × NA

### Step 4: Calculate the number of atoms in 8 grams of SO2
1. **Find the molar mass of SO2:**
- Sulfur (S) = 32 g/mol
- Oxygen (O) = 16 g/mol
- Molar mass of SO2 = 32 + (16 × 2) = 32 + 32 = 64 g/mol

2. **Calculate the number of moles of SO2:**
- Number of moles = Given weight / Molar mass = 8 g / 64 g/mol = 1/8 moles

3. **Calculate the number of atoms in SO2:**
- Each molecule of SO2 contains 3 atoms (1 S + 2 O).
- Number of atoms = Moles × Avogadro's number × 3 = (1/8) × NA × 3 = (3/8) × NA

### Summary of the number of atoms in each option:
- CO2: (3/4) × NA
- H2: 4 × NA
- NH3: (20/17) × NA
- SO2: (3/8) × NA

### Conclusion:
The largest number of atoms is found in option B (4 grams of H2), which contains 4 × NA atoms.