Question

How many grams of Pb are contained in a mixture of 0.135 kg each of PbCl(OH) and Pb2Cl2CO3?

Answer 1

Hey there!:

Given the mass of PbCl(OH) :

0.135 Kg = 0.135 Kg*(1000g / 1Kg)  = 135 g

Molecular mass of PbCl(OH)  = 207+35.5+16+1  = 259.5 g / mol

Atomic mass of Pb = 207 g/mol

Hence mass of Pb in 135 g  PbCl(OH)  :

(207 g Pb /  259.5 g PbClOH) * 135g PbClOH  =

0.79768 * 135 =>  107.68 g of Pb

For Pb2Cl2CO3  :

Given the mass of Pb2Cl2CO3  :

0.135 Kg = 0.135 Kgx(1000g / 1Kg)  = 135 g

Molecular mass of Pb2Cl2CO3  = 2*207+2*35.5+12+3*16  = 545 g / mol

Mass of Pb present in 1 mol (=545 g / mol) of Pb2Cl2CO3  = 2*207 = 414 g

Hence mass of Pb in 135 g  Pb2Cl2CO3:

(414 g Pb /  545 g PbClOH) * 135g PbClOH  =

0.75963 * 135 => 102.55 g of Pb2Cl2CO3

Hope that helps!

Answer 2

Answer: Mass of lead in $PbCl(OH)$ is 107.74 g and mass of lead in $Pb_2Cl_2CO_3$ is 103.6 g

Explanation:

To calculate the number of moles, we use the equation:

$\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}$      .....(1)

• For PbCl(OH):

Given mass of PbCl(OH) = 0.135 kg = 135 g   (Conversion factor:  1 kg = 1000 g)

Molar mass of PbCl(OH) = 259.66 g/mol

Putting values in equation 1, we get:

$\text{Moles of PbCl(OH)}=\frac{135g}{259.66g/mol}=0.52mol$

In 1 mole of PbCl(OH), 1 mole of lead, 1 mole of chlorine, 1 mole of hydrogen and 1 mole of oxygen atoms are present.

Moles of lead = $(1\times 0.52)=0.52mol$

Calculating the mass of lead in PbCl(OH) by using equation 1, we get:

Molar mass of lead atom = 207.2 g/mol

Moles of lead atom = 0.52 moles

Putting values in equation 1, we get:

$0.52mol=\frac{\text{Mass of lead atom}}{207.2g/mol}\\\\\text{Mass of lead atom}=107.74g$

Mass of lead atom = 107.74 g

• For $Pb_2Cl_2CO_3$:

Given mass of $Pb_2Cl_2CO_3$ = 0.135 kg = 135 g

Molar mass of $Pb_2Cl_2CO_3$ = 545.3 g/mol

Putting values in equation 1, we get:

$\text{Moles of }Pb_2Cl_2CO_3=\frac{135g}{545.3g/mol}=0.25mol$

In 1 mole of $Pb_2Cl_2CO_3$, 2 moles of lead, 2 moles of chlorine, 1 mole of carbon and 3 moles of oxygen atoms are present.

Moles of lead = $(2\times 0.25)=0.50mol$

Calculating the mass of lead in $Pb_2Cl_2CO_3$ by using equation 1, we get:

Molar mass of lead atom = 207.2 g/mol

Moles of lead atom = 0.50 moles

Putting values in equation 1, we get:

$0.50mol=\frac{\text{Mass of lead atom}}{207.2g/mol}\\\\\text{Mass of lead atom}=103.6g$

Mass of lead atom = 103.6 g

Hence, mass of lead in $PbCl(OH)$ is 107.74 g and mass of lead in $Pb_2Cl_2CO_3$ is 103.6 g