Answer:
B
Explanation:
This is because conductivity depends on the mobility of electrons.
When aluminum metal is made to contact with chlorine gas (Cl₂), a highly exothermic reaction proceeds. This produces aluminum chloride (AlCl₃) powder. The balanced chemical equation for this reaction is shown below:
2Al(s) + 3Cl₂(g) → 2AlCl₃(s)
Since it was stated that aluminum is in excess, this means that the amount of AlCl₃ produced will only depend on the amount of Cl₂ gas available. The molar mass of Cl₂ is 70.906 g/mol. Using stoichiometry, we have the following equation:
(21.0 g Cl₂/ 70.906 g/mol Cl₂) x 2 mol AlCl₃/ 2 mol Cl₂ = 0.1974 mol AlCl₃
Thus, we have determined that 0.1974 <span>moles of aluminum chloride can be produced from 21.0 g of chlorine gas. </span>
The number of particles (molecules or atoms) is: 6.022 x 10²³ particles (atoms or molecules).
1 mol of H₂O has 6.022 x 10²³ molecules.
1 mol of Al has 6.022 x 10²³ atoms.
The metal is lead, Pb.
One unit of the oxide contains one atom of O (16.00 u).
∴ Mass of oxide = 16.00 u O × (100 u MO/7.17 u O) = 223.15 u MO
Mass of M = mass of MO – mass of O = 223.15 u -16.00 u = 207.2 u
The only element with an atomic mass of 207.2 u is lead (Pb) and the formula of the oxide is PbO.
