Ch.2 - Atoms, Molecules, and Ions

Brown - Chemistry: The Central Science 14th Edition

Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232당신이 사용하는 게 아니라요?교과서 변경

Brown 14th Edition

Ch.2 - Atoms, Molecules, and Ions

문제 90b

2장, 문제 90b

(b) How many molecules of C13H18O2 are in this tablet?

검증된 단계별 안내

Determine the molar mass of C_{13}H_{18}O_{2} by adding the atomic masses of all atoms in the formula.

Use the given mass of the tablet to find the number of moles of C_{13}H_{18}O_{2} using the formula: \( \text{moles} = \frac{\text{mass}}{\text{molar mass}} \).

Use Avogadro's number (6.022 \(\times\) 10^{23} molecules/mol) to convert moles of C_{13}H_{18}O_{2} to molecules.

Multiply the number of moles by Avogadro's number to find the total number of molecules.

Ensure all units are consistent and cancel appropriately to verify the calculation process.

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주요 개념

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Molecular Formula

The molecular formula of a compound indicates the number and type of atoms present in a molecule. For C13H18O2, it shows that each molecule contains 13 carbon atoms, 18 hydrogen atoms, and 2 oxygen atoms. Understanding the molecular formula is essential for calculating the number of molecules in a given mass of the substance.

Avogadro's Number

Avogadro's number, approximately 6.022 x 10^23, is the number of atoms, ions, or molecules in one mole of a substance. This constant allows chemists to convert between the number of moles and the number of individual molecules, which is crucial for determining how many molecules are present in a specific quantity of a compound.

Molar Mass

The molar mass of a compound is the mass of one mole of that substance, typically expressed in grams per mole (g/mol). For C13H18O2, calculating the molar mass involves summing the atomic masses of all atoms in the molecular formula. This value is necessary for converting grams of the substance to moles, which can then be used to find the number of molecules.

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교과서 질문

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912

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교과서 질문

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1045

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교과서 질문

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488

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교과서 질문

"The diameter of a rubidium atom is 495 pm We will consider two different ways of placing the atoms on a surface. In arrangement A, all the atoms are lined up with one another to form a square grid. Arrangement B is called a close-packed arrangement because the atoms sit in the 'depressions' formed by the previous row of atoms:

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674

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