An aqueous solution containing 17.5 g of an unknown molecular compound in 100.gwater was found to have a freezing point of -1.8°C. Calculate the molar mass of thisunknown compound. You can use the following steps to solve this problem. Showyour work.a. What is the freezing point change (AT) from pure water? The freezing point ofwater is 0.0°C.b. What is the freezing point depression constant (K₂) of water?c. What is the molality of the solution? (m=d. Solve the moles of the solute.moles of solutekg of solvente. Knowing the mass of the compound, and the moles of the compound, solve themolar mass of the compound.

Given,The mass of unknown molecular compound = 17.5 gThe mass of water = 100. gThe freezing point…

An aqueous solution containing 17.5 g of an unknown molecular compound in 100.g water was found to have a freezing point of -1.8°C. Calculate the molar mass of this unknown compound. You can use the following steps to solve this problem. Show your work. a. What is the freezing point change (ATA) from pure water? The freezing point of water is 0.0°C. b. What is the freezing point depression constant (K) of water? c. What is the molality of the solution? (m= d. Solve the moles of the solute. moles of solute kg of solvent e. Knowing the mass of the compound, and the moles of the compound, solve the molar mass of the compound.

An aqueous solution containing 17.5 g of an unknown molecular compound in 100.g water was found to have a freezing point of -1.8°C. Calculate the molar mass of this unknown compound. You can use the following steps to solve this problem. Show your work. a. What is the freezing point change (ATA) from pure water? The freezing point of water is 0.0°C. b. What is the freezing point depression constant (K) of water? c. What is the molality of the solution? (m= d. Solve the moles of the solute. moles of solute kg of solvent e. Knowing the mass of the compound, and the moles of the compound, solve the molar mass of the compound.

Chemistry: Principles and Practice

3rd Edition

ISBN:9780534420123

Author:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Publisher:Daniel L. Reger, Scott R. Goode, David W. Ball, Edward Mercer

Chapter12: Solutions

Section: Chapter Questions

Problem 12.95QE

See similar textbooks

Related questions

Q: The molal freezing point depression constant K = 3.50 °C-kg-mol X, the solution freezes at -8.0 °C.…

A: Consider the given information as follows;

Q: The normal freezing point of a certain liquid X is -4.4 °C, but when 12.06 g of urea freezes at -8.3…

A: The normal freezing point of a certain liquid X is -4.4o CWhen 12.06 g of urea is dissolved in 350…

Q: 15.A solution was made by dissolving 10.00 g of an unknown nonelectrolyte compound in 105.0 g of…

A: In given question ∆Tf= Kf×m formula used

Q: -4 At 25.0 °C the Henry's Law constant for nitrogen trifluoride (NF, gas in water is 7.9 x 10…

Q: Determine the freezing point of a solution that contains 75.9 g of rhophthalene (C11H7) dissolved in…

A: mass of rhophthalene (C11H7) = 75.9 gVolume of rhozene = 739 mLDensity of rhozene = 0.83…

Q: Lab report – investigating solubility of solids in water and interpreting the solubility curves.…

A: "As you have asked multiple qs in a single post, I am helping you with first three as per the…

Q: 3. A 0.2436-g sample of an unknown substance was dissolved in 20.0 mL of cyclohexane. The density of…

Q: Look at the solubility curves on the graph below and then answer the following Solubility Chart for…

A: Note: As per the guidelines, solutions of first 3 subparts have been made. For the expert solutions…

Q: 1.86 g of unknown C were dissolved in 8.00 ml of water in a large test tube. The test tube was…

A: Colligative properties: The colligative properties are those properties of solutions that depend on…

Q: What is the solubility of Bi2S3 in g/L (At. Mass: Bi = 209; S =32 ). Ksp Bi2S3= 1.6 x 10-72 Answer…

A: The equilibrium between the soluble ions and insoluble salt can be described by the solubility…

Q: A certain substance X has a normal freezing point of 0.5 °C and a molal freezing point depression…

A: mass of urea = 21.87 gmolar mass of (NH2)2CO = 60.06 g/molKf = 4.05oC kg/molT(solvent) = 0.5oCi = 1…

Q: Sodium chloride (NaCl) has a solubility of 36.0 g/100 g H₂O at 20 °C. Select the temperature at…

A: Solubility may be defined as the property of a solvent to solubilize a solute in fixed amount of…

Q: The expressions for boiling point elevation and freezing point depression apply accurately to dilute…

A: Colligative property

Q: Questions: 1. CHM-202 Lab 2 Freezing Point Depression Rev2 G6-2022 10/14 From your understanding of…

A: Hi! Thank you for the question As per the honor code, We'll answer the first question since the…

Q: A certain liquid X has a normal freezing point of -4.00 °C and a freezing point depression constant…

Q: Match the term with the related statement. Amixture with particles that settle out if undisturbed.…

A: A question to match about colloidal properties, which is to be accomplished.

Q: What is the solubility of Bi2S3 in g/L (At. Mass: Bi = 209; S =32 ). Ksp BizS3= 1.6 x 10-72 Answer…

Q: Ckated stateement. A mixture with particles that settle out if undisturbed. The visible erratic…

Q: Prove the statement that an alternative way to express Henry's law of gas solubility is to say that…

A: Henry law explains the solubility of a gas in liquid solution by partial pressure and mole fraction…

Q: When 2.43 g of a certain molecular compound X are dissolved in 65. g of formamide (NH₂COH), the…

A: As we know, Depression in freezing point, Tf° - Tf = i * Kf * mWhere Tf° & Tf are freezing…

Q: 1. Using the freezing point of the solutions and the freezing point of the pure solvent, calculate…

A: To determine the molar mass of the solute for the run 2-5 in part A and calculate the percentage…

Q: Calculate the solubility of nitrogen gas in solution if the pressure of the gas mixture above the…

A: Molar mass of N2 - 28 g/mol Molar mass of O2 - 32 g/mol Molar mass of CO2 - 44 g/mol Given, KH - 6.1…

Q: Why is potassium hydrogen phthalate (KHP) used to standardize the NaOH solution instead of measuring…

A: Given:

Q: When 2.19 g of a certain molecular compound X are dissolved in 100. g of formamide (NH, COH), the…

A: To Calculate molar mass , we would first Calculate depression in freezing point using freezing point…

Q: (NH,),CO) The normal freezing point of a certain liquid X is – 4.4 °C, but when 14.0 g of urea are…

A: The molal freezing point depression constant Kf of X can be calculated by using the formula as:…

Q: Use the solubility curve below to determine how much NANO3 can dissolve in 300 g of water at 10…

A: The given graph is plotted between solubility and temperature. This shows the dependence of…

Q: When 634, mg of a certain molecular compound X are dissolved in 60. g of cyclohexane (CH2), the…

Q: The freezing point depression constant for benzene is 5.06 °C/m and the freezing point of pure…

Q: 3. 2 g of NacI is dissolved in 500 g of water at 35°C. Determine the ff: PNacI • 2.16 cm a. Boiling…

A: Kf for water=1.86 °C/m Kb for water= 0.52 °C/m

Q: A geochemist measures the concentration of salt dissolved in Lake Parsons and finds a concentration…

A: Note: As per the guidelines solution of first question has been made. For the expert solution of…

Q: When 605. mg of a certain molecular compound X are dissolved in 100 g of cyclohexane (CH₂), the…

A: GivenWeight of unknown compound X = 605. mg = 0.605 gWeight of solvent = 100. gFreezing point of…

Q: When a nonvolatile solute such as ammonium sulfate is dissolved in a solvent like water, one of the…

Q: Find the freezing point of a solution of 990 g of CH3OH in 2.5 kg of water. Use the water…

A: Colligative properties: The colligative properties are those properties of solutions that depend on…

Q: At 45°C, the vapor in equilibrium with a solution of ethanol (eth) and chloroform (chl) has a…

A: We have find out the partial pressures in the vapor phase. b. Calculate pure chloroform's vapor…

Q: 2. You have a solution that contains 4.0g of oxalic acid dissolved in 100 mL of water. This solution…

A: Given:9.5 g of Oxalic acid Is soluble in 100 mL of water.16.9 g of Oxalic acid is soluble in 100 mL…

Q: Jumbled below are the steps to making a solution. Place the steps in the correct order (step 1 = 1,…

Concept explainers

Solutions

Solutions can be considered as homogeneous mixtures which contain two or more than two chemical substances. The chemical substance which is the greater part is defined as solvent. And the chemical substance that is dissolved in a solvent is referred to as solute. Solution chemistry plays an important role in chemistry since it supports many commercial applications of solutions.

Question

An aqueous solution containing 17.5 g of an unknown molecular compound in 100.g
water was found to have a freezing point of -1.8°C. Calculate the molar mass of this
unknown compound. You can use the following steps to solve this problem. Show
your work.
a. What is the freezing point change (AT) from pure water? The freezing point of
water is 0.0°C.
b. What is the freezing point depression constant (K₂) of water?
c. What is the molality of the solution? (m=
d. Solve the moles of the solute.
moles of solute
kg of solvent
e. Knowing the mass of the compound, and the moles of the compound, solve the
molar mass of the compound.

Expert Solution

This question has been solved!

Explore an expertly crafted, step-by-step solution for a thorough understanding of key concepts.

This is a popular solution!

SEE SOLUTION Check out a sample Q&A here

Step 1: Determine the molar mass of unknown molecular compound from the given data:

VIEW

Step 2: (a) Calculation for freezing point change of pure water:

VIEW

Step 3: (b) The Kf of water is:

VIEW

Step 4: (c) Calculation for molality of the solution:

VIEW

Step 5: (d) Calculation for moles of unknown compound:

VIEW

Step 6: (e) Calculation for molar mass of the compound:

VIEW

Solution

VIEW

Trending now

This is a popular solution!

Step by step

Solved in 7 steps with 6 images

SEE SOLUTION Check out a sample Q&A here

Knowledge Booster

Learn more about

Need a deep-dive on the concept behind this application? Look no further. Learn more about this topic, chemistry and related others by exploring similar questions and additional content below.

Similar questions

Vapor-pressure lowering is a colligative property, as are freezing-point depression and boiling-point elevation. What is a colligative property? Why is the freezing point depressed for a solution as compared to the pure solvent? Why is the boiling point elevated for a solution as compared to the pure solvent? Explain how to calculate T for a freezing-point depression problem or a boiling-point elevation problem. Of the solvents listed in Table 10-5, which would have the largest freezing-point depression for a 0.50 molal solution? Which would have the smallest boiling-point elevation for a 0.50 molal solution? A common application of freezing-point depression and boiling-point elevation experiments is to provide a means to calculate the molar mass of a nonvolatile solute. What data are needed to calculate the molar mass of a nonvolatile solute? Explain how you would manipulate these data to calculate the molar mass of the nonvolatile solute.
Sodium chloride (NaCl) is commonly used to melt ice on roads during the winter. Calcium chloride (CaCl2) is sometimes used for this purpose too. Let us compare the effectiveness of equal masses of these two compounds in lowering the freezing point of water, by calculating the freezing point depression of solutions containing 200. g of each salt in 1.00 kg of water. (An advantage of CaCl2 is that it acts more quickly because it is hygroscopic, that is. it absorbs moisture from the air to give a solution and begin the process. A disadvantage is that this compound is more costly.)
A forensic chemist is given a white solid that is suspected of being pure cocaine (C17H21NO4, molar mass = 303.35 g/mol). She dissolves 1.22 0.01 g of the solid in 15.60 0.01 g benzene. The freezing point is lowered by 1.32 0.04C. a. What is the molar mass of the substance? Assuming that the percent uncertainty in the calculated molar mass is the same as the percent uncertainty in the temperature change, calculate the uncertainty in the molar mass. b. Could the chemist unequivocally state that the substance is cocaine? For example, is the uncertainty small enough to distinguish cocaine from codeine (C18H21NO3, molar mass = 299.36 g/mol)? c. Assuming that the absolute uncertainties in the measurements of temperature and mass remain unchanged, how could the chemist improve the precision of her results?
You have read that adding a solute to a solvent can both increase the boiling point and decrease the freezing point. A friend of yours explains it to you like this: The solute and solvent can be like salt in water. The salt gets in the way of freezing in that it blocks the water molecules from joining together. The salt acts like a strong bond holding the water molecules together so that it is harder to boil. What do you say to your friend?
You make 20.0 g of a sucrose (C12H22O11) and NaCl mixture and dissolve it in 1.00 kg water. The freezing point of this solution is found to be 0.426C. Assuming ideal behavior, calculate the mass percent composition of the original mixture, and the mole fraction of sucrose in the original mixture.
An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of the compound gives mass percents of 31.57% C and 5.30% H. The molar mass is determined by measuring the freezing-point depression of an aqueous solution. A freezing point of 5.20C is recorded for a solution made by dissolving 10.56 g of the compound in 25.0 g water. Determine the empirical formula, molar mass, and molecular formula of the compound. Assume that the compound is a nonelectrolyte.
A compound contains 42.9% C, 2.4% H, 16.6% N, and 38.1% O. The addition of 3.16 g of this compound to 75.0 mL of cyclohexane (d=0.779g/mL) gives a solution with a freezing point at 0.0C. Using Table 10.2, determine the molecular formula of the compound.
You drop an ice cube (made from pure water) into a saltwater solution at 0C. Explain what happens and why.
From the data presented in Figure 12.11, determine which has the more positive enthalpy of solution: NaCl or NH4Cl. Explain.
You dissolve 1.0 mol of urea (H2NCONH2) in 270 g of water. The mole fraction of urea is (a) 3710 3 (b) 0.063 (c) 16 (d) 1.0 and its molality is (a) 1.0 (b) 3.7 (c) 0.063 (d) 0.27
a. Use the following data to calculate the enthalpy of hydration for calcium chloride and calcium iodide. Lattice Energy Hsoln CaCl2(s) 2247kj/mol 46kj/mol Cal2(s) 2059kj/mol 104kj/mol b. Based on your answers to part a, which ion, Cl or I, is more strongly attracted to water?
Consider 2 vapor pressure curves A and B. They are the vapor pressure curves of pure benzene and a contaminated solution of benzene with a nonvolatile solute. (a) Which graph shows the vapor pressure curve for pure benzene? (b) What is the boiling point of the contaminated benzene solution? (c) Estimate the molality of the contaminated solution (k b=2.53C/m).