From the chemical formula, 1 formula unit of KAl (SO4)2.12H2O
encompasses 1 atom of Al = 4 * 2 atoms of O in KAl (SO4)2 + 12 atoms of O in
12H2O which is equal to 20 atoms of O.
So, if you have 1.3 × 10^21 Al atoms, you have 20 * 1.3 × 10^21 O atoms will
now be equal to 2.6 * 10^22 atoms of O.
Answer: The number of oxygen atoms in given amount of alum are [tex]2.53\times 10^{22}[/tex]
Explanation:
To calculate the number of moles, we use the equation:
[tex]\text{Number of moles}=\frac{\text{Given mass}}{\text{Molar mass}}[/tex]
Given mass of alum = 1 g
Molar mass of alum = 477.3884 g/mol
Putting values in above equation, we get:
[tex]\text{Moles of alum}=\frac{1g}{477.3884g/mol}=0.0021mol[/tex]
In 1 mole of [tex]KAl(SO_4)_2.12H_2O[/tex], 1 mole of aluminium atom, 20 moles of oxygen atoms, 1 mole of potassium atom, 2 moles of sulfur atom and 21 moles of hydrogen atoms are present.
According to the mole concept:
1 mole of a substance contains [tex]6.022\times 10^{23}[/tex] number of atoms.
So, 0.0021 moles of alum will contain [tex]20\times 0.0021\times 6.022\times 10^{23}=2.53\times 10^{22}[/tex] number of oxygen atoms.
Hence, the number of oxygen atoms in given amount of alum are [tex]2.53\times 10^{22}[/tex]
