Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 3: Q68 E (page 172)

The US Environmental Protection Agency (EPA) places limits on the quantities of toxic substances that may be discharged into the sewer system. Limits have been established for a variety of substances, including hexavalent chromium, which is limited to 0.50 mg/L. If an industry is discharging hexavalent chromium as potassium dichromate K2Cr2O7, what is the maximum permissible molarity of that substance?

Short Answer

Expert verified

The maximum permissible molarity for K2Cr2O7is \(1.7 \times {10^{ - 6}}M\)

Step by step solution

01

Given Data

Molarity = number of moles / liter of solution

Given

1 mol K = 39.098 g

1 mol Cr = 51.996 g

1 mol O = 15.999 g

02

Determine the mass

Calculation

Molar Mass

\(\begin{align}{K_2}C{r_2}{O_7} &= 2\left( {39.098} \right) + 2\left( {51.996} \right) + 7\left( {15.999} \right)\\ &= 294.181gmo{l^{ - 1}}\end{align}\)

Molarity = number of moles / liter of solution

Substitute the values in the formula above.

\(0.50\frac{{mg}}{L}\left( {\frac{{1g}}{{1000mg}}} \right)\left( {\frac{{1\,mol}}{{294.181g}}} \right) = 1.7 \times {10^{ - 6}}\frac{{mol}}{L} = 1.7 \times {10^{ - 6}}M\)

Therefore,maximum permissible molarity for K2Cr2O7is \(1.7 \times {10^{ - 6}}M\)

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

Which contains the greatest number of moles of oxygen atoms: 1 mol of ethanol (C2H5OH), 1 mol of formic acid (HCO2H), or 1 mol of water (H2O)? Explain why.

What volume of a 1.50-MKBr solution contains 66.0 g KBr?

A 55-kg woman has 7.5 × 10−3 mol of hemoglobin (molar mass = 64,456 g/mol) in her blood. How many hemoglobin molecules is this? What is this quantity in grams?

What mass of a 4.00% NaOH solution by mass contains 15.0 g of NaOH?

What is the concentration of the NaCl solution that results when 0.150 L of a 0.556-M solution is allowed to evaporate until the volume is reduced to 0.105 L?
See all solutions

Recommended explanations on Chemistry Textbooks

Making Measurements

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation

Nuclear Chemistry

Read Explanation

Chemical Analysis

Read Explanation

Organic 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.

Sign-up for free