Cinnamic alcohol is used mainly in perfumery, particularly...

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 $0.469 \mathrm{~g} ?$

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 $0.469 \mathrm{~g} ?$

Key Concepts

Avogadro's Number

Avogadro's number, approximately 6.022 x 10^23, is the number of atoms, molecules, or other particles present in one mole of a substance. It allows chemists to calculate the number of discrete particles in a given mass of material, which is essential for understanding chemical reactions on a molecular level and for quantifying substances in laboratory settings.

Percent Composition

Percent composition refers to the percentage by mass of each element in a compound. It is calculated by dividing the total mass of the element in one mole of the compound by the compound’s molar mass, then multiplying by 100. This concept is important for understanding the makeup of chemical compounds and for applications such as quality control in chemical synthesis.

Mole Concept

The mole concept is a fundamental principle in chemistry that defines the amount of substance. It relates the mass of a substance to the number of particles it contains (typically atoms or molecules) through Avogadro's number. This concept is critical for converting between mass and number of entities in stoichiometric calculations.

Molecular Formula

A molecular formula represents the number and type of atoms in a molecule. It serves as the starting point for determining the compound's molar mass and for calculating the proportions of different elements within the molecule. Understanding the molecular formula is essential for further stoichiometric calculations and compositional analyses.

Molar Mass Calculation

Molar mass is the mass of one mole of a substance, calculated by summing the masses of all individual atoms in the molecular formula. This value is crucial for converting between the mass of a sample and the number of moles, which is the basis for quantitative chemical calculations.

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