Question

3a. Calculate the required mass of an unknown nonelectrolyte (ℳ = 125.7998 g/mol) dissolved in 129.7 g of solvent that gives a solution that freezes at 1.85 °C. The freezing point of the pure solvent is 4.44 °C and its K_f value is 1.87 °C/m.

Report your answer to TWO places past the decimal.

3b. Calculate the molar mass (in g/mol) of an unknown nonelectrolyte if 0.613 g dissolved in 250.3 mL of water at 19.47 °C has an osmotic pressure of 17.2 mmHg.

R = 0.082058 L⋅atm⋅mol⁻¹⋅K⁻¹. 1.00 atm = 760 mmHg. Report your answer to THREE significant figures.

3c. The solubility of carbon monoxide gas at 44.1 °C and a carbon monoxide pressure of 507 mmHg is 2.26 × 10⁻³ g/L. What is the Henry's Law constant in mol⋅L⁻¹⋅atm⁻¹?

Report your answer to THREE significant figures. You may (but are not required to) enter your answer in scientific notation; for example, if your answer is 2.44 × 10⁻², you would enter 2.44E-2. The E must be uppercase.

3d. Calculate the molar mass (in g/mol) of an unknown 1:1 electrolyte if 0.429 g dissolved in 218.5 mL of water at 70.83 °C has an osmotic pressure of 53.1 mmHg.

R = 0.082058 L⋅atm⋅mol⁻¹⋅K⁻¹. 1.00 atm = 760 mmHg. Report your answer to THREE significant figures.

3e. What is the solubility (in mol/L) of oxygen gas at a pressure of 0.652 atm? The Henry's Law constant, K_H is 1.32 × 10⁻³ mol⋅L⁻¹⋅atm⁻¹.

Report your answer to THREE significant figures. You may (but are not required to) enter your answer in scientific notation; for example, if your answer is 2.44 × 10⁻², you would enter 2.44E-2. The E must be uppercase.

please answer all parts, try not to round and show your work. Thank you so much!

take all the time you need :)

Answer 1

a. Calculate the molality of the solution ぴ= freezing point of the pure solvent= 4.44°C T freezing point of the solution 1.85°C KF freezing constant: 1.87 °C/m m- molality 4.44°C 1.85°C 1.87-m 4.44°C-1.85°C 1.87 1.29 m m Calculate the moles of solute (the unknown nonelectrolyte) moles solute molality m - solvent mass (kg) moles solute 1.29 m = 0.1297 kg mol moles solute kg 1.29- 0.1297 kg 1.29x 0.1297 kg -moles solute 0.167 mol moles solute mol

Calculate the necessary mass of the unknown nonelectrolyte mass nonelectrolyte 125.7998 g nonelectrolyte 1 mol nonelectrolyte 0.167 mol nonelectrolyte χ -21.05 g nonelectrolyte

3.b Calculate the molarity (M) π=MRT π= osmotic pressure: 17.2 mmHg π = 17.2 mm1Hg x 760 mmHg 1 atm = 0.0226 atm M= molarity R= ideal gas constant= 0.082 atm LK mol T= temperature= 19.47°C + 273=292.5 K atm L 0.0226 atm Mx 0.082 x 292.5 K K mol 0.0226 atm atm L K mol x 292.5 K 0.000942 M = M =M Calculate the moles of the nonelectrolyte solute moles Molarity = M = solution volume (L)

0.000942 mol nonelectrolyte 1000 ml moles nonelectrolyte = 250.3 mL x 0.000236 mol nonelectrolyte Calculate the molar mass (M) of the nonelectrolyte 0.613 g 0.000236 mol M= = 2.60 x 10° mol Henry's Law C gas concentration 1 mol CO 28 g CO mo 2.26 x 10-3 gCO = 8.07 x 10-5 C x kHenry's Law constant P- gas pressure p = 507 mm1Hg x 7601n,nHg 1 atm 0.667 atm mol -= k x 0.667 atm 8.07 x 10-5

mol 8.07 x 10-s m0L 0.667 atm 1.21 x 10-4 mol L-1 atm1 k 1.21 E 4 mol L atmk 3d Calculate the molarity (M) π = iMRT t osmotic pressure 1 atm π = 53.1 mimHg x 0.0699 atm 760 mmHg M= molarity R= ideal gas constant-0082058 atm LK mol T temperature-70.83 °C + 273-343.8 K Vanit Hoff factor- number of ions that are present when the electrolyte is dissociated in solution. In this case, the relation between the ions is 1:1 so that, j 2 atm L 0.0699 atm 2 x M x 0.082058x 343.8 K K mol

0.0699 atm 2 x 0.082058 K mol atm x 343.8 K 0.00 124 M = M Calculate the moles of the electrolyte solute moles Molarity = M = solution volume (L) 0.00124 mol electrolyte 1000 mL moles nonelectrolyte 218.5 mL = 0.000271 mol electrolyte Calculate the molar mass (M) of the electrolyte 0.429 g_1R103 0.000271 mol - 1.58 x mol