Logout Open In App
Open In App
Warning: foreach() argument must be of type array|object, bool given in /var/www/html/web/app/themes/studypress-core-theme/template-parts/header/mobile-offcanvas.php on line 20

Chapter 13: Q. 13.18 (page 329)

Why is iodine sometimes introduced into a tungsten lamp?

Short Answer

Expert verified

The interaction between iodine and gaseous tungsten produces volatile WI2, which extends the filament's life

Step by step solution

01

Step 1. Given information

A minor amount of lodine is included within the quartz envelope that houses the tungsten filament in tungsten/halogen lights. A tungsten/halogen lamp has a life span that is more than double that of a standard lamp, thanks to the inclusion of iodine.

02

Step 2. Iodine in tungsten lamp

The interaction between iodine and gaseous tungsten produces volatile WI2, which extends the filament's life. When this compound's molecules collide with the filament. Tungsten is redeposited as a result of decomposition. The halogen is then released, and the cycle begins again.

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

Define

(a) dark current.

(b) transducer.

(c) scattered radiation (in a monochromator).

(d) source flicker noise.

(e) cell positioning uncertainty.

(f) beamsplitter.

A compound Xis to be determined by UV-visible spectrophotometry. A calibration curve is constructed from standard solutions of Xwith the following results: 0.50ppm, A=0.24; 1.5ppm, A=0.36; 2.5ppm, A=0.44;3.5ppm,A=0.59;4.5ppm,A=0.70. A solution of unknown Xconcentration had an absorbance of A=0.50. Find the slope and intercept of the calibration curve, the standard error in Y, the concentration of the solution of unknown X concentration, and the standard deviation in the concentration of X. Construct a plot of the calibration curve and determine the unknown concentration by hand from the plot. Compare it to that obtained from the regression line.

The absorbances of solutions containing K2CrO4 in 0.05 M KOH were measured in a 1.0-cm cell at 375 nm.

The following results were obtained:

Conc. of K2CrO4, g/L
A at 375 nm
0.00500.123

0.0100

0.247
0.0200
0.494
0.03000.742
0.0400
0.991

Find the absorptivity of the chromate ion, CrO42-inL.g-1cm-1and the molar absorptivity of chromate in L.mol-1cm-1at 375 nm.

Calculate the absorbance of solutions having twice the percent transmittance of those in Problem 13-2.

The absorbances of solutions containing Cr as dichromate Cr2O7-2in 1.0MH2SO4were measured at 440nm in a 1.0-cm cell.

Find the absorptivity of dichromateLg-1cm-1and the molar absorptivity Lmol-1cm-1at 440nm.

The following results were obtained:
See all solutions

Recommended explanations on Chemistry Textbooks

Organic Chemistry

Read Explanation

Kinetics

Read Explanation

Inorganic Chemistry

Read Explanation

Chemistry Branches

Read Explanation

Chemical Reactions

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.

Sign-up for free