Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 13: Q 1. (page 499)

Question: What is the mass of the molecular ion formed from compounds having each molecular formula:

(a) C3H6O; (b)C10H20;(c)C8H8O2; (d) methamphetamine (C10H15N)?

Short Answer

Expert verified

Answer

a. 58

b. 140

c. 136

d. 149

Step by step solution

01

Molecular ion

A molecular ion is formed by the bombardment of the given molecule with electron beams. It is a cation with a single unit positive charge and a radical with an unpaired electron.

02

Mass of molecular ions

Since the mass of the departing electron is almost negligible concerning the mass of the molecule, the mass of the molecular ion thus formed remains the same as the original molecule.

03

Determination of the mass

a. The mass of is the total mass of its substituents.

C3H6O = 3×12 + 6×1 + 1×16= 36 + 6 + 16= 58

Hence, the mass of the molecular ion of C3H6O is 58.


b. The mass of is the total mass of its substituents.

C10H20 = 10×12 + 20×1 = 120 + 20 = 140

Hence, the mass of the molecular ion of C10H20is 140.

c. The mass of is the total mass of its substituents.

C8H8O2 = 8×12 + 8×1 + 2×16= 96 + 8 + 32= 136

Hence, the mass of the molecular ion of C8H8O2 is 136.

d. The mass of is the total mass of its substituents.

C10H15N = 10×12 + 15×1 + 1×14= 120 + 15 + 14= 149

Hence, the mass of the molecular ion of C10H15N is 149.

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

Question:Propose two possible structures for a hydrocarbon having an exact mass of 96.0939 that forms ethylcyclopentane upon hydrogenation with H2 and Pd-C.

Question:2,3-Dimethylbutane and 2,2-dimethylbutane have the same molecular ion in the mass spectrum, but only one of these isomers gives a significant fragment at m/z= 57.

(a) Whichisomer shows an intense peak at m/z= 57?

(b) Propose a structure for the ion that gives riseto this peak.

(c) The base peak in the mass spectrum of the other isomer occurs at m/z= 43.

What ion gives rise to this peak?

Question:Propose four possible structures for a hydrocarbon with a molecular ion at m/z= 112.

Oxidation of citronellol, a constituent of rose and geranium oils, with PCC in the presence of added NaOCOCH3 forms compound A. A has a molecular ion in its mass spectrum at 154 and a strong peak in its IR spectrum at 1730 cm-1. Without added NaOCOCH3, oxidation of citronellol with PCC yields isopulegone, which is then converted to B with aqueous base. B has a molecular ion at 152, and a peak in its IR spectrum at 1680 cm-1.

a. Identify the structures of A and B.

b. Draw a mechanism for the conversion of citronellol to isopulegone.

c. Draw a mechanism for the conversion of isopulegone to B.

Question: Match each compound to its IR spectrum.
See all solutions

Recommended explanations on Chemistry Textbooks

Chemistry Branches

Read Explanation

The Earths Atmosphere

Read Explanation

Chemical Analysis

Read Explanation

Inorganic Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Nuclear 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