Cinnamic alcohol is used mainly in perfumery, particularly in soaps and cosmetics. Its molecular for\(\begin{array}{lll}\text { mula is } & \text { C }_{9} \text { H }_{10} \text { O. }\end{array}\) (a) Calculate the percent composition by mass of \(\mathrm{C}, \mathrm{H},\) and \(\mathrm{O}\) in cinnamic alcohol. (b) How many molecules of cinnamic alcohol are contained in a sample of mass \(0.469 \mathrm{~g} ?\)

Short Answer

Expert verified
The mass percentage compositions of each element in cinnamic alcohol are: 72.73 \% C, 8.56 \% H, and 18.71 \% O. The 0.469 g sample of cinnamic alcohol contains approximately \(2.4 * 10^{21}\) molecules.

Step by step solution

01

Finding the molar mass of cinnamic alcohol

First, find the molar mass of cinnamic alcohol using the molecular formula \(C_{9}H_{10}O\) and the atomic masses of Carbon (C), Hydrogen (H), and Oxygen (O). The molar mass is calculated as follows: \(9 * MolarMass(C) + 10 * MolarMass(H) + 1 * MolarMass(O)\). The atomic masses of C, H and O are approximately 12.01 g/mol, 1.008 g/mol and 16.00 g/mol respectively. Plugging these values and calculating yields the molar mass as \(118.18\) g/mol.
02

Calculating the percent composition

The percent by mass of each element is calculated by dividing the total mass contributed by the element in the molecule by the molar mass of the molecule, and then multiplying by 100. For Carbon: \((9 * MolarMass(C)/ MolarMass(C9H10O)) * 100\%. For Hydrogen: \((10 * MolarMass(H) / MolarMass(C9H10O)) *100\%. And for Oxygen: \(MolarMass(O) / MolarMass(C9H10O) *100\) \%. Inputting the values for each element and calculating yields the mass percentage of Carbon as 72.73 \%, Hydrogen as 8.56 \% and Oxygen as 18.71 \%.
03

Calculating the number of molecules

To find the number of molecules in the given mass of cinnamic alcohol we first find the number of moles of cinnamic alcohol in 0.469 g using the equation Moles = mass/molar mass, yielding the moles of cinnamic alcohol in 0.469 g as 0.004 moles. We then multiply the moles of cinnamic alcohol by Avogadro's number \(6.022 * 10^{23}\) to find the number of molecules. The calculated result is approximately \(2.4 * 10^{21}\) molecules.
04

Final Conclusions

The percent composition by mass of \(C_{9}H_{10}O\) is approximately 72.73 \% C, 8.56 \% H and 18.71 \% O. The number of molecules of cinnamic alcohol in 0.469 g is approximately \(2.4 * 10^{21}\) molecules.

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 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

See all solutions

Recommended explanations on Chemistry Textbooks

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