Answer:
Due to the difference in the relative atomic masses and therefore, the molecular masses of Zn and Pb, one mole of Zn is about 3.2 times lighter than one mole of Pb
Explanation:
From the periodic table, we have;
The atomic number of zinc, Zn = 30
The atomic mass of zinc, Zn = 65.38 amu
The molar mass of zinc, Zn = 65.38 g/mol
The atomic number of lead, Pb = 82
The atomic mass of lead, Pb = 207.2 amu
The molar mass of lead, Pb = 207.2 g/mol
Therefore, whereby equal number of moles of Zn is lost and Pb is gained, we have;
Mass of 1 mole of Zn = 65.38 grams
Therefore, 1 gram of Zn = 1/65.38 moles = 0.0153 moles
0.12 grams of Zn = 0.12×0.0153 = 0.00184 moles of Zn
Given that equal number of moles of Zn and Pb are involved in the reaction, the number of moles of Pb gained = 0.00184 moles
The mass of Pb gained = Number of moles of Pb gained × Molar mass of Pb
The mass of Pb gained = 0.00184 × 207.2 = 0.38 g ≈ 0.4 g.
Amount of Pb gained = 0.43 g ≈ 0.4 g
