Question

how to put formulate the question :
Calculate the number of atoms present in 3.752g sample of Pb? 

Answer 1

Answer :-   atom of Pb

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Explanation :-

Given :-  Mass of Pb = 3.752 g

we know, Molar mass of Pb = 207 g/mol

To calculate number of atoms present in 3.752 g Pb, we first calculate number of moles of Pb in 3.752 g and then this number of moles is multiply by Avogadro's number.

Formula :-

Therefore,

mole of Pb = = 0.01813 mol

we know that,

According to Avogadro's law,

1 mol of substance = atoms of substance

Thus, we have,

1 mol of Pb = atoms of Pb

therefore,

0.01813 mol of Pb =  

=

=   of Pb

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