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Question
Compute the difference in masses of 103 moles each of magnesium atoms and magnesium ions.
(Mass of an electron = 9.1×10–31 kg)
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Solution
Mg+2ion = 10 electron
Mg atom = 12 electrons
Difference between Mg2+ and Mg = 2 moles of electrons
The difference between 103 moles of Mg and 103 moles of Mg2+ = 103 × 2 moles of electrons
Mass of 103 × 2 moles of electrons
= 2 × 103 × 6.022 × 1023 × 9.1 × 10−31 kg
= 1.096 × 10−3 kg
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