How Accurate Is Gravimetric Analysis in Determining Mineral Composition?

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Gravimetric analysis is discussed in the context of determining the mineral composition of a geological sample containing Boulangerite (Pb5Sb4S11). A 6.34-g sample yields 3.80 g of PbCl2 after chemical treatment, prompting a calculation of the percentage by mass of Pb5Sb4S11 in the sample. Participants suggest using the relationship between moles and mass to derive the composition, emphasizing the need for the total number of moles of lead to find the moles of the original mineral. The conversation highlights the importance of understanding the chemical equations involved in the analysis. Overall, the thread focuses on the practical application of gravimetric analysis for mineral composition determination.
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The Title should actually be "Gravimetric Analysis"

srry about that but i can't change it now :(

1.
A 6.34-g geological sample, containing the mineral Boulangerite (Pb5Sb4S11) as the only lead-bearing compound, is subjected to chemical treatment in which the lead is quantitatively recovered as solid PbCl2. The mass of PbCl2 obtained is 3.80 g.
What was the percentage (by mass) of Pb5Sb4S11 in the sample?



2. n=m/MM
%yield= (actual yield over theoretical yield) * 100




3. Well I am guessing the equation is something like

Pb5Sb4S11 -------> PbCl2(s)

how to get cl in there or SbS out :S

mass is given as 3.8g


I have no clue
can someone can get me started atleast?
 
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salman213 said:
The Title should actually be "Gravimetric Analysis"

srry about that but i can't change it now :(

1.
A 6.34-g geological sample, containing the mineral Boulangerite (Pb5Sb4S11) as the only lead-bearing compound, is subjected to chemical treatment in which the lead is quantitatively recovered as solid PbCl2. The mass of PbCl2 obtained is 3.80 g.
What was the percentage (by mass) of Pb5Sb4S11 in the sample?



2. n=m/MM
%yield= (actual yield over theoretical yield) * 100

3. Well I am guessing the equation is something like

Pb5Sb4S11 -------> PbCl2(s)

how to get cl in there or SbS out :S

mass is given as 3.8g


I have no clue
can someone can get me started atleast?

If you knew the total number of moles of lead in the original sample could you use it to find out how many moles of Pb_5Sb_4S_{11} were in the original sample?
 
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