Which of the following substances contains the greatest mass...

Which of the following substances contains the greatest mass of chlorine?
(a) $5.0 \mathrm{~g} \mathrm{Cl}_{2},$
(b) $60.0 \mathrm{~g}\mathrm{NaClO}_{3}$
(c) $0.10 \mathrm{~mol} \mathrm{KCl}$,
(d) $30.0 \mathrm{~g} \mathrm{MgCl}_{2}$,
(e) $0.50 \mathrm{~mol} \mathrm{Cl}_{2}$.

Key Concepts

Mass Percent Composition

Mass percent composition is the fraction of the total mass of a compound that is contributed by a specific element. It is calculated by dividing the total mass of the element in one mole of the compound by the molar mass of the compound, then multiplying by 100, and is useful for comparing the relative amounts of an element in different substances.

Stoichiometry

Stoichiometry involves the quantitative relationships in a chemical formula, determining how atoms combine in fixed ratios. It is used to calculate the number of atoms of a specific element present in a given amount of a compound, based on the compound's formula.

Mole Concept

The mole is a unit that measures the amount of a substance. It relates the number of particles in a given mass of substance to Avogadro's number, allowing chemists to convert between moles and mass based on the substance's molar mass.

Molar Mass

Molar mass is the mass of one mole of a chemical substance and is expressed in grams per mole. It allows for conversion from the number of moles to the mass of a substance, which is essential for comparing amounts of elements within different compounds.

Transcript

00:01 In this problem, we need to determine which of these compounds contains the most of the chlorine.

00:09 So chlorine exists as a diatomic molecule as cl2.

00:18 However, if we do the math, we actually can just convert to cl instead of cl2.

00:24 We actually end up with the same answer.

00:27 So i will show you what i mean as we go over this.

00:30 So for a, we have five grams of cl2.

00:33 Know what is the mass of chlorine.

00:35 So what we're going to do is basically we see we have five grams of co2 and let's try converting it to moles of the co2.

00:50 So if you find the atomic mass of chlorine from periodic table and multiply that by two, we get the mass of diatomic chlorine co2.

00:58 So the grams cancel out.

01:01 We get moles of cl2.

01:03 In one mole of co2, we have two moles of dcl.

01:07 Because the subscript on the cl is 2.

01:10 So therefore, we say that we can convert to moles of chlorine.

01:14 And then we're going to use the atomic mass of the chlorine to convert to the mass of chlorine.

01:22 The moles of chlorine cancels out.

01:24 And we end up getting 5 grams of chlorine if we calculate this.

01:27 So you can see that we actually have the same mass of the cl as we do the cl2.

01:35 So mathematically, it actually works out to be.

01:38 Exactly the same.

01:40 So for the other problems, we actually can either convert to cl2 or cl.

01:47 So let's do the next one.

01:49 So for 60 grams of nacl of 3, divide by the molar mass of that, and then we get moles of the nacl of 3.

02:06 Then in one mole of this, we have one mole of the cl...

Please give Ace some feedback