1. 0.1 mol Pb (A)
2. 0.334 (A)
3. 144 g(C)
4. 2 moles (A)
5. 32 g SO₂(B)
6. 24 g C (no option)
Further explanation
A mole is a unit of many particles (atoms, molecules, ions) where 1 mole is the number of particles contained in a substance that is the same amount as many atoms in 12 gr C-12
1 mole = 6.02.10²³ particles
While the number of moles can also be obtained by dividing the mass (in grams) with the molar mass of element or molecule
So looking for moles we can search in 2 ways
1 . Avogadro's number
n = N : No
N = number of gas particles
No = Avogadro number (6.02.10²³)
n = number of moles
2. Molar mass
n = m : M
m = mass
M = relative molecular mass
1. moles Lead :
= mass : Molar mass Pb
= 20.7 g : 207.2 g/mol
= 0.1 mol Pb (A)
2. moles Magnesium :
= N : No
= 2.01 x 10²³ : 6.02 x 10²³
= 0.334 (A)
3. mass HCl(molar mass=36 g/mol) :
= mol x Molar mass
= 4 x 36
= 144 g(C)
4. moles CO₂
= mass : molar mass CO₂
= 88 : 44 g/mol
= 2 moles (A)
5. mass SO₂
= mol x molar mass SO₂
= 0.5 x 64
= 32 g SO₂(B)
6. mass Carbon
= mol x molar mass Carbon
= 2 x 12
= 24 g C (no option)
