Molecular weight of lead(ii) nitrate Pb(NO_3)_2

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Discussion Overview

The discussion revolves around the calculation of the molecular weight of lead(II) nitrate, Pb(NO3)2, as presented in a specific example from a chemistry textbook. Participants are comparing their calculated values with the value provided in the book and exploring potential discrepancies.

Discussion Character

  • Debate/contested

Main Points Raised

  • One participant calculates the molecular weight of Pb(NO3)2 as 331.2 g/mol, while the book states it as 283.2 g/mol.
  • Another participant agrees with the 331.2 g/mol calculation and suggests the book is incorrect.
  • Some participants express surprise at the possibility of an error in a textbook and question the reliability of online sources that provide the same solution.
  • It is noted that the molar mass discrepancy could be due to a calculation error in the book, specifically suggesting that it may have been calculated for PbN2O3 instead.

Areas of Agreement / Disagreement

Participants generally disagree on the accuracy of the textbook's molecular weight, with some asserting that the book is wrong while others express skepticism about the reliability of the sources that replicate the book's value.

Contextual Notes

The discussion highlights potential errors in published materials and the challenges of verifying scientific information across different sources.

Paul Black
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Hello everyone
I am trying to solve the following question from the book Analytical Chemistry 7th edition by Gard D. Christian - Page 164 Example 5.17
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My problem is when I calculate the molecular weight of Pb(NO_3)_2 I get 331.2 g/mol but in the book they get 283.2 g/mol . Could you explain to me where they get this number. So instead of getting 0.137 g as last result, I get 0.16 g.

Also googling the question always gets me the same solution.
 
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Paul Black said:
when I calculate the molecular weight of Pb(NO_3)_2 I get 331.2 g/mol

That's what I got as well, book is wrong.
 
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First time I see an error in a book.
So in that case all the internet pages that have the same question+solution made the same mistake. Do they just copy past ?
 
Paul Black said:
First time I see an error in a book.

Lucky you.

So in that case all the internet pages that have the same question+solution made the same mistake. Do they just copy past ?

Apparently.

The molar mass they used is off by 48, which is exactly three oxygen atoms, as if they had calculated molar mass for PbN2O3.
 
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Thank you for your help
Will see if this book has more mistakes.
 

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