Curie radium

Marie Curie determined the atomic weight of radium by analysis of the following reaction, which goes to completion quantitatively:
RaCl2 (aq) + 2 AgNO3 (aq) -- > 2 AgCl (s) + Ra(NO3)2 (aq) .
When she dissolved 0.09192 g of RaCl2 and mixed it with excess silver nitrate solution, she collected 0.08890 g of AgCl. Take the molar mass of Ag to be 107.8 g/mol and of Cl to be 35.4 g/mol.

a) How many moles of AgCl did Curie collect?

b) How many moles of RaCl2 did she dissolve?

c) Compute the molar mass of RaCl2 based on Curie's data.

d) Determine the molar mass of Ra based on Curie's data.

Reference

Marie Curie, "Sur le poids atomique du radium," Comptes Rendus 135, 161-163 (1902). Marie Curie, Doctoral Thesis (1903); English translation published as Radioactive Substances (Philosophical Library: New York, 1961).
Copyright 2003 by Carmen Giunta. Permission is granted to reproduce for non-commercial educational purposes.

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