Answer:
number of moles = 6.393 moles
Explanation:
One mole of any substance contains Avogadro's number (6.022 * 10^23) of atoms.
Therefore, to know the number of moles that contain 3.85 * 10^24 atoms, all we have to do is cross multiplication as follows:
1 mole ......................> 6.022 * 10^23
?? moles ..................> 3.85 * 10^24
number of moles = (3.85 * 10^24 *1) / (6.022 * 10^23)
number of moles = 6.393 moles
Hope this helps :)
The reaction is not balanced
<h3>Further explanation</h3>
Given
Reaction
2Fe(s)+3O₂(g)⇒2Fe₂O₃(s)
Required
The number of atoms
Solution
In a balanced chemical equation, the number of atoms in the compound that reacts (the reactants and products) will have the same number
Reactants : Fe(s)+O₂(g)
Fe = 2 atoms
O = 3 x 2 = 6 atoms
Products : Fe₂O₃(s)
Fe = 2 x 2 = 4 atoms
O = 2 x 3 = 6 atoms
The reaction is not balanced because the number of Fe atoms is not the same
The balanced reaction should be:
4Fe(s)+3O₂(g)⇒2Fe₂O₃(s)
Answer: They can be separated by physical processes.
Explanation: A mixture is made up of two or more substances that are not chemically combined and can be easily separated into its constituents by physical methods.
Answer:
the compound contains C, H, and some other element of unknownidentity, so we can’t calculate the empirical formula
Explanation:
Mass of CO2 obtained = 3.14 g
Hence number of moles of CO2 = 3.14g/44.0 g = 0.0714 mol
The mass of the carbon in the sample = 0.0714 mol × 12.0g/mol = 0.857 g
Mass of H2O obtained = 1.29 g
Hence number of moles of H2O = 1.29g/18.0 g = 0.0717 mol
The mass of the carbon in the sample = 0.0717 mol × 1g/mol = 0.0717 g
% by mass of carbon = 0.857/1 ×100 = 85.7 %
% by mass of hydrogen = 0.0717/1 × 100 = 7.17%
Mass of carbon and hydrogen = 85.7 + 7.17 = 92.87 %
Hence, there must be an unidentified element that accounts for (100 - 92.87) = 7.13% of the compound.
