A chemist is given a nonelectrolyte white powder for analysis. 38.7 g of this substance is dissolved in 100.0 g of water. It is determined that the resulting solution freezes at –4.0°C. Additionally, the elemental composition of the substance is identified and found to be 40.0% C, 6.7% H and 53.3 % O by mass. Find the molecular formula of this unknown white powder using these experimental evidences (Kf of water: 1.86°C/m, C: 12 g/mol, H: 1 g/mol, O: 16 g/mol)

The boiling point of water is 100.00 °C at 1 atmosphere. A student dissolves 11.57 grams of manganese(II) iodide, MnI, (308.7 g/mol), in 221.5 grams of water. Use the table of boiling and freezing point constants to answer the questions below. Solvent Formula Kp (°C/m) Kf (°C/m) Water H2O 0.512 1.86 Ethanol CH3CH,OH 1.22 1.99 Chloroform CHCI3 3.67 Benzene 2.53 5.12 Diethyl ether CH3CH2OCH2CH3 2.02 The molality of the solution is m. The boiling point of the solution is °C.

The normal boiling point of a certain liquid X is 141.40 °C, but when 20. g of glycine (C,H,NO2) are dissolved in 250. g of X the solution boils at 142.6 °C instead. Use this information to calculate the molal boiling point elevation constant K, of X. Round your answer to 2 significant digits. olo °C·kg K, = ] x10 Ar mol ?

The molal freezing point depression constant =Kf·7.96°C·kgmol−1 for a certain substance X. When 5.40g of urea NH22CO are dissolved in 200.g of X, the solution freezes at −4.9°C. Calculate the freezing point of pure X. Round your answer to 2 significant digits.

Select the one with the highest boiling point. Select the one with the lowest freezing point. A. 1.0 m KNO3 B. 0.75 m NaCl C. 0.75 m CuCl₂ D. 2.0 m C12H22O11 (sucrose) E. pure water Determine the freezing point of a solution that contains 0.31 mol of sucrose in 175 g of water, where K₁ = 1.86°C/m. A. 3.3°C Your answer: B. 1.1°C C. 0.0°C D. -1.1°C E. -3.3°C

q 2req Visited 2req [Review Topics] [References] Use the References to access important values if needed for this question. The boiling point of ethanol, CH3 CH₂OH, is 78.500 °C at 1 atmosphere. Kb (ethanol) = 1.22 °C/m In a laboratory experiment, students synthesized a new compound and found that when 10.17 grams of the compound were dissolved in 204.5 grams of ethanol, the solution began to boil at 78.723 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound? g/mol Submit Answer Q Graph_08-30-2....pdf NO Retry Entire Group O J A 9 more group attempts remaining I' 6 Previous Next> Show all 11:15 PM 9/12/2022

Calculate the freezing point and boiling point for 0.43 molmol ethylene glycol and 0.17 mol KBrmol KBr in 124 gg H2OH2O.         Express your answer using one decimal place.

At a given temperature, you have a mixture of ethanol and acetone at 19.5 °C. The vapor pressure of pure ethanol at 19.5 °C is 42.28 mmHg and the vapor pressure of pure acetone at 19.5 °C is 180.5 mmHg. The mole fraction of ethanol in the solution is 0.819. Assuming ideal behavior, calculate the mole fraction of acetone in the vapor above the solution, in mmHg.

The normal freezing point of a certain liquid X is 0.10 °C, but when 18. g of potassium bromide (KBr) are dissolved in 400. g of X the solution freezes at -1.2 °C instead. Use this information to calculate the molal freezing point depression constant K, of X. Round your answer to 2 significant digits. K₁ = 1 °C kg mol 1 D

The boiling point of chloroform, CHCl3, is 61.700 °C at 1 atmosphere. Kb(chloroform) = 3.67 °C/m In a laboratory experiment, students synthesized a new compound and found that when 14.11 grams of the compound were dissolved in 204.7 grams of chloroform, the solution began to boil at 62.577 °C. The compound was also found to be nonvolatile and a non-electrolyte. What is the molecular weight they determined for this compound ? _____g/mol