What is the percentage composition of #PbCl_2#?

Question

Jeremiah Adams · Accepted Answer

#"74.504% Pb"#
#"25.496% Cl"# The molar masses of the constituent elements, the number of moles of the compound itself, and their respective molar masses can all be used to determine the percent composition of a given compound. As you know, a compound's molar mass tells you what the mass of one mole of that substance is. The molar mass of lead(II) chloride is equal to #"278.106 g/mol"#, which means that one mole of lead(II) chloride will have a mass of #"278.106 g"#. Currently, a single mole of lead(II) chloride will have The molar masses of these two ions are equal to #"207.2 g/mol"# for #"Pb"^(2+)# and #"35.453 g/mol"# for #"Cl"^(-)#. Thus, one mole of lead(II) chloride will have the following contents: #1 color(red)(cancel(color(black)("mole Pb"^(2+)))) * "207.2 g"/(1color(red)(cancel(color(black)("mole Pb"^(2+))))) = "207.2 g Pb"^(2+)# additionally #2 color(red)(cancel(color(black)("moles Cl"^(-)))) * "35.453 g"/(1color(red)(cancel(color(black)("mole Cl"^(-))))) = "70.906 g Cl"^(-)# This indicates that lead(II) chloride's percentage composition will be #( 70.906 color(red)(cancel(color(black)("g"))))/(278.106color(red)(cancel(color(black)("g")))) xx 100 = color(green)("25.496% Cl")# #( 207.2 color(red)(cancel(color(black)("g"))))/(278.106color(red)(cancel(color(black)("g")))) xx 100 = color(green)("74.504% Pb")# So, every mole of lead(II) chloride will contain #"70.906 g"# of chlorine and #"207.2 g"# of lead. This is equivalent to saying that every #"100 g"# of lead(II) chloride will contain #"25.496 g"# of chlorine in the form of chloride anions and #"74.504 g"# of lead in the form of lead(II) cations.

Natalie Anton · Answer

undefined To determine the percentage composition of PbCl2, we need to know the molar mass of each element and the molecular formula of PbCl2.

The molar mass of Pb (lead) is approximately 207.2 g/mol, and the molar mass of Cl (chlorine) is approximately 35.45 g/mol.

The molecular formula of PbCl2 indicates one lead atom (Pb) and two chlorine atoms (Cl).

The total molar mass of PbCl2 is:
1 * molar mass of Pb + 2 * molar mass of Cl
= 207.2 g/mol (Pb) + 2 * 35.45 g/mol (Cl)
= 207.2 g/mol + 70.9 g/mol
= 278.1 g/mol

Now, to find the percentage composition of each element:
Percentage of Pb = (Mass of Pb / Molar mass of PbCl2) * 100
= (207.2 g / 278.1 g) * 100
≈ 74.57%

Percentage of Cl = (Mass of Cl / Molar mass of PbCl2) * 100
= (2 * 35.45 g / 278.1 g) * 100
≈ 25.43%

Therefore, the percentage compos