The formula for mole fraction is:
-(1)
The solubility of oxygen gas = 1.0 mmol/L (given)
1.0 mmol/L means 1.0 mmol are present in 1 L.
Converting mmol to mol:
So, moles of oxygen = 0.001 mol
For moles of water:
1 L of water = 1000 mL of water
Since, the density of water is 1.0 g/mL.
So, the mass of water is 1000 g.
Molar mass of water = 18 g/mol.
Number of moles of water =
Substituting the values in formula (1):
Hence, the mole fraction is .
Atomic Mass will be 23 the new magnesium formed will be its isotope of magnesium.
We know that,
In stable condition
Number of electrons = Number of protons
Atomic number represents number of proton .
So, here number of proton is 12
Therefore, number of electron is 12
We know that -
Atomic mass = number of protons +Number of neutron
So if magnesium loses one neutron i.e. new number of neutron is 11
then its atomic mass changes.
New atomic mass will be
Atomic mass =
Atomic mass = 23
This new element with atomic mass 23 and atomic number 12 is the isotope of magnesium.
To know more about isotopes
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