Answer:
4 moles of H₃PO₄
Explanation:
The reaction expression is given as;
3KOH + H₃PO₄ → K₃PO₄ + 3H₂O
Number of moles of water = 12moles
Unknown:
Number of moles of H₃PO₄ = ?
Solution:
From the balanced reaction expression we see that;
3 moles of water is produced from 1 mole of H₃PO₄
So; 12 moles of water would be produced from = 4 moles of H₃PO₄
Answer:
Density of unit cell ( rhodium) = 12.279 g/cm³
Explanation:
Given that:
The radius (r) of a rhodium atom = 135 pm
The atomic mass of rhodium = 102.90 amu
For a face-centered cubic unit cell,
where;
a = edge length.
Making "a" the subject of the formula:
a = 381.8 pm
to cm, we get:
a = 381.8 × 10⁻¹⁰ cm
However, recall that:
where;
mass of unit cell = mass of atom × numbers of atoms per unit cell
Also;
Recall also that number of atoms in a unit cell for a face-centered cubic = 4
So;
mass of unit cell = 6.83380375 × 10⁻²² g
Density of unit cell ( rhodium) = 12.279 g/cm³