Skip to main content
Ch.3 - Molecules, Compounds & Chemical Equations
Chapter 3, Problem 86

How many bromine atoms are present in 35.2 g of CH2Br2?

Verified step by step guidance
1
Calculate the molar mass of CH2Br2 by adding the atomic masses of all the atoms in the compound: C (12.01 g/mol), H (1.01 g/mol each), and Br (79.90 g/mol each).
Determine the number of moles of CH2Br2 in 35.2 g by using the formula: \( \text{moles} = \frac{\text{mass}}{\text{molar mass}} \).
Recognize that each molecule of CH2Br2 contains 2 bromine atoms.
Calculate the total number of bromine atoms by multiplying the number of moles of CH2Br2 by Avogadro's number (\(6.022 \times 10^{23}\) molecules/mol) and then by 2 (since there are 2 Br atoms per molecule).
Express the final result as the total number of bromine atoms present in the given mass of CH2Br2.

Verified Solution

Video duration:
2m
This video solution was recommended by our tutors as helpful for the problem above.
Was this helpful?

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

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 CH2Br2, the molar mass can be determined by adding the masses of carbon (C), hydrogen (H), and bromine (Br) atoms, which is essential for converting grams of the compound to moles.
Recommended video:
Guided course
02:11
Molar Mass Concept

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 relate the mass of a substance to the number of particles it contains. In this context, it will be used to determine how many bromine atoms are present in the moles of CH2Br2 calculated from the given mass.
Recommended video:
Guided course
01:45
Avogadro's Law

Stoichiometry

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between the reactants and products in a chemical reaction. It allows for the calculation of the amount of substances involved based on their molar ratios. In this case, stoichiometry will help determine the number of bromine atoms in the given mass of CH2Br2 by using the mole ratio from the molecular formula.
Recommended video:
Guided course
01:16
Stoichiometry Concept