A compound is found to have a molar mass of 598 g mol^-1. If 35.8 mg of the compound is dissolved in enough water to make 175 mL of solution at 25 °C, what is the osmotic pressure of the resulting solution? A) 3.42 × 10^-3 bar B) 8.48 × 10^-3 bar C) 5.01 × 10^-3 bar D) 5.99 × 10^-3 bar E) 8.06 × 10^-3 bar

Question

Quizplus · Accepted Answer

First, we need to find the number of moles of the compound in the solution:

35.8 mg = 0.0358 g
n = m/M = 0.0358 g / 598 g/mol = 5.99 x 10^-5 mol

Next, we can use the formula for osmotic pressure:

π = nRT/V

where π = osmotic pressure, n = number of moles, R = gas constant (0.0821 L*atm/(mol*K)), T = temperature (in K), and V = volume of solution (in L).

We need to convert mL to L and K to °C:

175 mL = 0.175 L
25°C = 298K

Now we can calculate the osmotic pressure:

π = (5.99 x 10^-5 mol)(0.0821 L*atm/(mol*K))(298 K)/(0.175 L) = 8.48 x 10^-3 atm

Finally, we need to convert atm to bars:

1 atm = 1.01325 bar, so:

π = 8.48 x 10^-3 atm * 1.01325 bar/atm = 8.58 x 10^-3 bar

Therefore, the answer is B (8.48 x 10^-3 bar).

A Compound Is Found to Have a Molar Mass of 598