Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 13: Problem 79

Adrenaline is the hormone that triggers the release of extra glucose molecules in times of stress or emergency. A solution of \(0.64 \mathrm{~g}\) of adrenaline in \(36.0 \mathrm{~g}\) of \(\mathrm{CCl}_{4}\) elevates the boiling point by \(0.49^{\circ} \mathrm{C}\). Is the molar mass of adrenaline calculated from the boiling-point elevation in agreement with the following structural formula?

Short Answer

Expert verified
The molar mass of adrenaline is approximately 182.34 g/mol.

Step by step solution

01

Find the molality of the solution

To find the molality, we need the moles of the solute (adrenaline) and mass of the solvent (\(\mathrm{CCl}_{4}\)) in kg. Since we don't have the moles of adrenaline, let's represent it by "n". Also, we need to convert the mass of \(\mathrm{CCl}_{4}\) to kg: Mass of \(\mathrm{CCl}_{4}\) in kg = \(36.0 \mathrm{~g}\) * \(\frac{1 \mathrm{~kg}}{1000 \mathrm{~g}} = 0.036 \mathrm{~kg}\) Molality (m) = \(\frac{n (moles\, of\, adrenaline)}{0.036\,\mathrm{kg\,of\,CCl}_{4}}\)
02

Apply the boiling point elevation formula

According to the formula, ΔT = m * K_b. We substitute the given values and the molality from the previous step: \(0.49^{\circ} \mathrm{C} = \frac{n (moles\, of\, adrenaline)}{0.036\,\mathrm{kg\,of\,CCl}_{4}} * 5.03 \,\mathrm{K\, kg\, mol}^{-1}\)
03

Find the moles of adrenaline

Solve the equation above for "n": \(n (moles\, of\, adrenaline) = \frac{0.49^{\circ} \mathrm{C} * 0.036\,\mathrm{kg\,of\,CCl}_{4}}{5.03 \,\mathrm{K\, kg\, mol}^{-1}} = 0.00351 \,\mathrm{mol}\)
04

Calculate the molar mass of adrenaline

To find the molar mass of adrenaline, we will divide the mass in grams by the number of moles: Molar mass of adrenaline = \(\frac{0.64 \,\mathrm{g}}{0.00351\,\mathrm{mol}} = 182.34 \,\mathrm{g\,mol^{-1}}\) The approximate molar mass of adrenaline is 182.34 g/mol.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

The enthalpy of solution of \(\mathrm{KBr}\) in water is about \(+198 \mathrm{~kJ} / \mathrm{mol}\). Nevertheless, the solubility of \(\mathrm{KBr}\) in water is relatively high. Why does the solution process occur even though it is endothermic?

Two beakers are placed in a sealed box at \(25^{\circ} \mathrm{C}\). One beaker contains \(30.0 \mathrm{~mL}\) of a \(0.050 \mathrm{M}\) aqueous solution of a nonvolatile nonelectrolyte. The other beaker contains \(30.0 \mathrm{~mL}\) of a \(0.035 \mathrm{M}\) aqueous solution of \(\mathrm{NaCl}\). The water vapor from the two solutions reaches equilibrium. (a) In which beaker does the solution level rise, and in which one does it fall? (b) What are the volumes in the two beakers when equilibrium is attained, assuming ideal behavior?

Indicate whether each of the following is a hydrophilic or a hydrophobic colloid: (a) butterfat in homogenized milk, (b) hemoglobin in blood, (c) vegetable oil in a salad dressing, (d) colloidal gold particles in water.

An ionic compound has a very negative \(\Delta H_{\text {soln }}\) in water. Would you expect it to be very soluble or nearly insoluble in water? Explain in terms of the enthalpy and entropy changes that accompany the process.

Ascorbic acid (vitamin \(\left.\mathrm{C}, \mathrm{C}_{6} \mathrm{H}_{8} \mathrm{O}_{6}\right)\) is a water-soluble vitamin. A solution containing \(80.5 \mathrm{~g}\) of ascorbic acid dissolved in \(210 \mathrm{~g}\) of water has a density of \(1.22 \mathrm{~g} / \mathrm{mL}\) at \(55^{\circ} \mathrm{C}\). Calculate (a) the mass percentage, (b) the mole fraction, (c) the molality, (d) the molarity of ascorbic acid in this solution.
See all solutions

Recommended explanations on Chemistry Textbooks

Organic Chemistry

Read Explanation

The Earths Atmosphere

Read Explanation

Inorganic Chemistry

Read Explanation

Nuclear Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemical Analysis

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.

Sign-up for free