The osmotic pressure of 6% solution of urea at 323 K is

Explanation

To calculate the osmotic pressure of a 6% solution of urea at 323 K, we can follow these steps:

### Step 1: Understand the formula for osmotic pressure
The osmotic pressure (π) can be calculated using the formula:
\[ \pi = CRT \]
where:
- \(C\) = concentration of the solute in moles per liter (mol/L)
- \(R\) = universal gas constant = 0.0821 L·atm/(K·mol)
- \(T\) = temperature in Kelvin (K)

### Step 2: Determine the concentration of urea
Given that we have a 6% solution of urea, this means there are 6 grams of urea in 100 mL of solution.

### Step 3: Convert grams to moles
To find the concentration in moles per liter, we first need to convert grams of urea to moles. The molecular weight of urea (NH₂CONH₂) is approximately 60 g/mol.

\[ \text{Number of moles of urea} = \frac{\text{mass (g)}}{\text{molecular weight (g/mol)}} = \frac{6 \text{ g}}{60 \text{ g/mol}} = 0.1 \text{ moles} \]

### Step 4: Convert volume from mL to L
The volume of the solution is given as 100 mL, which we need to convert to liters:
\[ \text{Volume in L} = \frac{100 \text{ mL}}{1000} = 0.1 \text{ L} \]

### Step 5: Calculate the concentration (C)
Now, we can calculate the concentration \(C\):
\[ C = \frac{\text{number of moles}}{\text{volume in L}} = \frac{0.1 \text{ moles}}{0.1 \text{ L}} = 1 \text{ mol/L} \]

### Step 6: Substitute values into the osmotic pressure formula
Now we can substitute the values into the osmotic pressure formula:
\[ \pi = CRT = (1 \text{ mol/L}) \times (0.0821 \text{ L·atm/(K·mol)}) \times (323 \text{ K}) \]

### Step 7: Calculate osmotic pressure
Now we perform the calculation:
\[ \pi = 1 \times 0.0821 \times 323 \approx 26.51 \text{ atm} \]

### Final Answer
The osmotic pressure of the 6% solution of urea at 323 K is approximately **26.51 atm**.

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