Calculate the number of moles in each sample: a. 72.5 g CCl4 b. 12.4 g C12H22O11 c. 25.2 kg C2H2 d. 12.3 g dinitrogen monoxide

Name: Chemistry: A Molecular Approach
Author: Tro
ISBN: 9780134112831

검증된 단계별 안내

insert step 1: Identify the molar mass of each compound.

insert step 2: Use the formula for moles: \( \text{moles} = \frac{\text{mass (g)}}{\text{molar mass (g/mol)}} \).

insert step 3: For each compound, divide the given mass by its molar mass to find the number of moles.

insert step 4: For CCl4, calculate the molar mass by adding the atomic masses of 1 C and 4 Cl atoms.

insert step 5: Repeat the process for C12H22O11, C2H2, and dinitrogen monoxide, using their respective molar masses.

주요 개념

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Molar Mass

Molar mass is the mass of one mole of a substance, typically expressed in grams per mole (g/mol). It is calculated by summing the atomic masses of all the atoms in a molecule. For example, the molar mass of carbon tetrachloride (CCl4) is determined by adding the atomic mass of carbon (12.01 g/mol) to four times the atomic mass of chlorine (35.45 g/mol). Knowing the molar mass is essential for converting grams to moles.

Mole Concept

The mole is a fundamental unit in chemistry that quantifies the amount of substance. One mole contains Avogadro's number of entities, approximately 6.022 x 10^23 particles, whether they are atoms, molecules, or ions. The mole concept allows chemists to relate mass to the number of particles, facilitating calculations in stoichiometry and chemical reactions.

Conversion from Grams to Moles

To convert grams of a substance to moles, the formula used is: moles = mass (g) / molar mass (g/mol). This conversion is crucial for stoichiometric calculations in chemical reactions, as it allows chemists to determine how much of a reactant is needed or how much product can be formed. Each sample in the question requires this conversion to find the number of moles present.