Westonci.ca is the ultimate Q&A platform, offering detailed and reliable answers from a knowledgeable community. Experience the convenience of getting reliable answers to your questions from a vast network of knowledgeable experts. Experience the ease of finding precise answers to your questions from a knowledgeable community of experts.

A student has synthesized a new compound (compound A, a nonelectrolyte). She uses osmotic pressure to determine the molar mass of compound A. She dissolves 0.50 g of compound A in water and prepares 15 mL of solution. At 25 C the osmotic pressure is 7.38 atm. Calculate the molar mass (g/mole) of compound A. Do not include a unit with your answer.

Sagot :

Answer:

110g/mol is the molar mass of compound A

Explanation:

The osmotic pressure of a solution could be obtained using the equation:

π = i*M*R*T -Solving molarity we can find the molar mass of the solute A-

Where π is osmotic pressure (7.38atm)

i is Van't Hoff's factor (1 for nonelectrolytes)

M is molarity (Our incognite)

R is gas constant (0.082atmL/molK)

T is absolute temperature (25°C + 273.15 = 298.15K)

Computing the values:

7.378atm = 1*M*0.082atmL/molK*298.15K

0.3018 mol/L is the concentration of the solution.

The volume of the solution is 15mL = 0.015L. Moles of the solute are:

0.3018 mol/L * 0.015L = 4.527x10⁻³ moles

Molar mass is the ratio between mass of the compound (0.50g) and the moles (4.527x10⁻³ moles). That is:

0.50g / 4.527x10⁻³ moles =

110g/mol is the molar mass of compound A

We hope this information was helpful. Feel free to return anytime for more answers to your questions and concerns. Thank you for visiting. Our goal is to provide the most accurate answers for all your informational needs. Come back soon. We're glad you visited Westonci.ca. Return anytime for updated answers from our knowledgeable team.