The number of H-atoms present in 5.6g urea are :-

Options

A. `6.02xx10^(23)`
B. `2.24xx10^(23)`
C. `2.24xx10^(22)`
D. `3.1xx10^(22)`

Explanation

To find the number of hydrogen atoms present in 5.6 g of urea, we can follow these steps:

### Step 1: Determine the molar mass of urea
Urea has the chemical formula \( \text{NH}_2\text{CO}\text{NH}_2 \). The molar mass can be calculated as follows:
- Nitrogen (N): 14 g/mol (2 Nitrogens = 2 x 14 = 28 g/mol)
- Carbon (C): 12 g/mol (1 Carbon = 12 g/mol)
- Oxygen (O): 16 g/mol (1 Oxygen = 16 g/mol)
- Hydrogen (H): 1 g/mol (4 Hydrogens = 4 x 1 = 4 g/mol)

Calculating the total:
\[ \text{Molar mass of urea} = 28 + 12 + 16 + 4 = 60 \text{ g/mol} \]

### Step 2: Calculate the number of moles of urea in 5.6 g
Using the formula for moles:
\[ \text{Number of moles} = \frac{\text{mass}}{\text{molar mass}} \]
Substituting the values:
\[ \text{Number of moles of urea} = \frac{5.6 \text{ g}}{60 \text{ g/mol}} = 0.0933 \text{ moles} \]

### Step 3: Determine the number of hydrogen atoms in one mole of urea
From the structure of urea, we see that one mole of urea contains 4 hydrogen atoms.

### Step 4: Calculate the total number of hydrogen atoms in 0.0933 moles of urea
Using the formula:
\[ \text{Total hydrogen atoms} = \text{Number of moles} \times \text{Number of hydrogen atoms per mole} \times \text{Avogadro's number} \]
Substituting the values:
\[ \text{Total hydrogen atoms} = 0.0933 \text{ moles} \times 4 \text{ H atoms/mole} \times 6.022 \times 10^{23} \text{ atoms/mole} \]

### Step 5: Perform the calculation
Calculating:
\[ \text{Total hydrogen atoms} = 0.0933 \times 4 \times 6.022 \times 10^{23} \approx 2.24 \times 10^{23} \text{ hydrogen atoms} \]

### Final Answer
The number of hydrogen atoms present in 5.6 g of urea is approximately \( 2.24 \times 10^{23} \).

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