[NewtoAtoms]

Hello chemists,

I have done the calculations and would someone be so kind to verify if I have done this correctly?
I am new to chemistry so any help would be greatly appreciated!

2 mL of 0.250 M of Pb(No3)2

a.  molar mass of Pb(NO3)2
     = (207.2g) + 2(14.01) + 6(16) = 331.22 g/mol
b.  how many moles in 331.22 g/mol
     = 0.250 m/L = x mols/ 0.002 L = 5 x 10^-4 mols Pb(NO3)2
c.  moles Pb(NO3)2 to grams
     = 331.22 g/mol = x grams/ 5 x 10^-4 mol Pb(NO3)2 = 0.16561 g pb(NO3)2
d.  grams Pb(NO3)2 to grams of Pb²⁺ ions
     = 0.16561 g Pb(NO3)2 x 1 mol/331.22 g Pb(NO3)2 x 1 mol Pb/1 mol Pb(NO3)2 x 207.2 g/1 mol pb = 0.1036 g Pb
e.  grams to moles
     = 0.1036 g / x mol x 207.2 g / 1 mol = 5 x 10^-4 mol

Is this correct or am I in left field?
how can there be 5 x 10^-4 moles of Pb 2+ ions in a solution (e) and 5 x 10^-4 moles in 331.22 g  Pb(NO3)2 (b)?

[Borek]

You are mostly OK, although there is something wrong here:

b.  how many moles in 331.22 g/mol
     = 0.250 m/L = x mols/ 0.002 L = 5 x 10^-4 mols Pb(NO3)2

What are you calculating? Number of moles in 2mL of 0.250M solution? You can't calculate number of "moles in 331.22 g/mol", it doesn't make sense. You can calculate number of moles in 331.22 g Pb(NO₃)₂, although - after calculating molar mass of lead(II) nitrate - it doesn't make sense, as it is obvious it is just 1 mole.