/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 33 What are the molarities of the f... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Problem 33

What are the molarities of the following solutes? (a) sucrose \(\left(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\right)\) if \(150.0 \mathrm{g}\) is dissolved per \(250.0 \mathrm{mL}\) of water solution (b) urea, \(\mathrm{CO}\left(\mathrm{NH}_{2}\right)_{2},\) if \(98.3 \mathrm{mg}\) of the \(97.9 \%\) pure solid is dissolved in \(5.00 \mathrm{mL}\) of aqueous solution (c) methanol, \(\mathrm{CH}_{3} \mathrm{OH},(d=0.792 \mathrm{g} / \mathrm{mL})\) if \(125.0 \mathrm{mL}\) is dissolved in enough water to make 15.0 L of solution

Short Answer

Expert verified
The molarities for the solutes are; (a) Sucrose solution: 2.08 M. (b) Urea solution: 3.13 M. (c) Methanol solution: 0.206 M.

Step by step solution

01

Compute Molarity of Sucrose Solution

Molar mass of sucrose \(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\) is \(342.3 \mathrm{g/mol}\). First, convert the given mass of sucrose (150.0 g) to moles using the molar mass. Secondly, the volume of water (250.0 mL) should be converted to liters, since molarity is defined in terms of liters of solution. Lastly, use the formula for molarity which is \(\text{M} = \frac{\text{moles of solute}}{\text{liters of solution}}\).
02

Compute Molarity of Urea Solution

The molar mass of urea, \(\mathrm{CO}\left(\mathrm{NH}_{2}\right)_{2}\), is \(60.06 \mathrm{g/mol}\). Given mass (98.3 mg) needs to be first converted to grams. Then, to take into account the purity, multiply the mass by 0.979. Convert this mass to moles using the molar mass. Convert the volume of water (5.00 mL) to liters. Finally, determine the molarity by dividing moles of solute by liters of solution.
03

Compute Molarity of Methanol Solution

The molar mass of methanol, \(\mathrm{CH}_{3} \mathrm{OH}\), is \(32.04 \mathrm{g/mol}\). With given volume (125.0 mL) and the density (0.792 g/mL), calculate the mass of methanol in grams. Convert this mass to moles. Then, use the total solution volume (15.0 L) to determine the molarity.

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.

Over 30 million students worldwide already upgrade their learning with 91影视!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Chemical Solutions
Chemical solutions are homogeneous mixtures composed of two or more substances. The component present in the largest amount is typically known as the solvent, and the other component(s) are solutes.
In aqueous solutions, water acts as the solvent, while the solute is the substance dissolved in water.
The concentration of a chemical solution refers to how much solute is present compared to the amount of solvent.
One common way to express concentration is the molarity (M), which is the number of moles of solute per liter of solution.
This makes it a crucial concept in chemistry for understanding reaction stoichiometry and chemical equilibria.
Molar Mass Calculation
Molar mass is an important concept that helps us relate the mass of a substance to the amount in moles. It is defined as the mass of one mole of a given substance, and is expressed in grams per mole (g/mol).
To calculate the molar mass of a compound, add up the atomic masses of all atoms present in one molecule of that compound. These atomic masses can be found on the periodic table.
Understanding molar mass allows chemists to measure out a precise amount of a substance for reactions or to determine the concentration of solutions. For example:
  • Sucrose \( ext{C}_{12} ext{H}_{22} ext{O}_{11}\) - The molar mass is 342.3 g/mol, calculated by adding up the atomic masses of 12 carbon, 22 hydrogen, and 11 oxygen atoms.
  • Urea \(\mathrm{CO}\left(\mathrm{NH}_{2}\right)_{2}\) - The molar mass is 60.06 g/mol by summing the masses of carbon, oxygen, and nitrogen atoms.
  • Methanol \(\mathrm{CH}_{3}\mathrm{OH}\) - Molar mass is 32.04 g/mol obtained by adding the masses of carbon, hydrogen, and oxygen atoms.
Molarity Formula
Molarity is a fundamental concept in chemistry that describes the concentration of a solute in a solution. It is defined by the formula:\[ M = \frac{\text{moles of solute}}{\text{liters of solution}} \]
To use this formula effectively, it is important to carefully carry out the following steps:
  • First, calculate the number of moles of the solute using its mass and molar mass. This involves dividing the mass of the solute (in grams) by its molar mass (in g/mol).
  • Second, convert the solution volume from milliliters to liters, because molarity is expressed in terms of liters. Remember that 1000 mL equals 1 L.
  • Lastly, apply the molarity formula by dividing the moles of solute by the liters of solution, providing the concentration in molarity (M).
Understanding this process helps in various applications such as preparing solutions with desired concentrations and conducting quantitative analyses in laboratory settings.

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

Iron ore is impure \(\mathrm{Fe}_{2} \mathrm{O}_{3} .\) When \(\mathrm{Fe}_{2} \mathrm{O}_{3}\) is heated with an excess of carbon (coke), metallic iron and carbon monoxide gas are produced. From a sample of ore weighing \(938 \mathrm{kg}, 523 \mathrm{kg}\) of pure iron is obtained. What is the mass percent \(\mathrm{Fe}_{2} \mathrm{O}_{3},\) by mass, in the ore sample, assuming that none of the impurities contain Fe?

A seawater sample has a density of \(1.03 \mathrm{g} / \mathrm{mL}\) and \(2.8 \% \mathrm{NaCl}\)l by mass. A saturated solution of \(\mathrm{NaCl}\) in water is \(5.45 \mathrm{M} \mathrm{NaCl} .\) How many liters of water would have to be evaporated from \(1.00 \times 10^{6} \mathrm{L}\) of the seawater before \(\mathrm{NaCl}\) would begin to crystallize? (A saturated solution contains the maximum amount of dissolved solute possible.)

Which has the higher concentration of sucrose: a \(46 \%\) sucrose solution by mass \((d=1.21 \mathrm{g} / \mathrm{mL}),\) or \(1.50 \mathrm{M}\) \(\mathrm{C}_{12} \mathrm{H}_{22} \mathrm{O}_{11}\) ? Explain your reasoning.

Given two liters of \(0.496 \mathrm{M} \mathrm{KCl},\) describe how you would use this solution to prepare \(250.0 \mathrm{mL}\) of \(0.175 \mathrm{M} \mathrm{KCl} .\) Give sufficient details so that another student could follow your instructions.

Azobenzene, an intermediate in the manufacture of dyes, can be prepared from nitrobenzene by reaction with triethylene glycol in the presence of \(\mathrm{Zn}\) and KOH. In one reaction, 0.10 L of nitrobenzene \((d=1.20 \mathrm{g} / \mathrm{mL})\) and \(0.30 \mathrm{L}\) of triethylene glycol \((d=1.12 \mathrm{g} / \mathrm{mL})\) yields \(55 \mathrm{g}\) azobenzene. What are the (a) theoretical yield, (b) actual yield, and (c) percent yield of this reaction? $$ 2 \mathrm{C}_{6} \mathrm{H}_{5} \mathrm{NO}_{2}+4 \mathrm{C}_{6} \mathrm{H}_{14} \mathrm{O}_{4} \frac{\mathrm{Zn}}{\mathrm{KOH}} $$ nitrobenzene triethylene glycol $$ \left(\mathrm{C}_{6} \mathrm{H}_{5} \mathrm{N}\right)_{2}+4 \mathrm{C}_{6} \mathrm{H}_{12} \mathrm{O}_{4}+4 \mathrm{H}_{2} \mathrm{O} $$ azobenzene
See all solutions

Recommended explanations on Chemistry Textbooks

The Earths Atmosphere

Read Explanation

Nuclear Chemistry

Read Explanation

Making Measurements

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Kinetics

Read Explanation

Physical Chemistry

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.