Answer :
To calculate the mass of a substance, you need to know the molar mass of the compound. The molar mass is the mass of one mole of a substance and is expressed in grams per mole (g/mol).
The molar mass of PbI2 (lead(II) iodide) can be calculated by adding the atomic masses of lead (Pb) and iodine (I), multiplied by their respective subscripts in the formula:
Molar mass of PbI2 = (atomic mass of Pb) + 2 × (atomic mass of I)
= (207.2 g/mol) + 2 × (126.9 g/mol)
= 207.2 g/mol + 253.8 g/mol
= 461 g/mol
To find the mass of 1.75 mol of PbI2, you can multiply the molar mass by the number of moles:
Mass = molar mass × number of moles
= 461 g/mol × 1.75 mol
= 805.75 g
Therefore, the mass of 1.75 mol of PbI2 is 805.75 grams.
Similarly, for FeCl2 (iron(II) chloride), the molar mass can be calculated by adding the atomic masses of iron (Fe) and chlorine (Cl), multiplied by their respective subscripts in the formula:
Molar mass of FeCl2 = (atomic mass of Fe) + 2 × (atomic mass of Cl)
= (55.8 g/mol) + 2 × (35.45 g/mol)
= 55.8 g/mol + 70.9 g/mol
= 126.7 g/mol
To find the mass of 6.25 mol of FeCl2:
Mass = molar mass × number of moles
= 126.7 g/mol × 6.25 mol
= 791.88 g
Therefore, the mass of 6.25 mol of FeCl2 is 791.88 grams.
Comparing the masses, we can see that 6.25 mol of FeCl2 has a greater mass than 1.75 mol of PbI2.
Learn more about atomic masses here:
https://brainly.com/question/29117302
#SPJ11
