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Intro to chem - mass question?
The rock in a lead ore deposit contains 84% PbS by mass. How many kilograms of the rock must be processed to obtain 1.0 kg of Pb?
I've been trying to get the answer for this problem for a while. Any ideas?
Thank you so much!
1 Answer
- Dr WLv 71 decade agoFavorite Answer
84% PbS means 84 kg PbS / 100 kg ore
% Pb in PbS = 207.2 / (207.2 + 32.1) = 0.866... meaning
86.6 kg Pb in 100 kg PbS....
still with me?
1.0 kg Pb x (100 kg PbS / 86.6 kg Pb) x (100 kg ore / 84 kg PbS) = 1.37 kg ore
ie.. you need to process 1.37 kg ore to get 1.00 kg Pb
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if you don't understand what I did here. ask in additional details
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your welcome. I keep repeating myself here on yahoo answers but learn dimensional analysis. aka unit factor method. aka factor label method. it makes problems like this quickly solveable. I think I spent about 2 min on this...
if you want info on dimensional analysis, ask in the details.. I'll check in about 15 min
