Answer:
Number of moles = 0.0005 mol.
Explanation:
Given data:
pH = 3
Volume of solution = 500 mL
Number of moles = ?
Solution:
HCl dissociate to gives H⁺ and Cl⁻
HCl → H⁺ + Cl⁻
It is known that,
pH = -log [H⁺]
3 = -log [H⁺]
[H⁺] = 10⁻³ M
[H⁺] = 0.001 M
Number of moles of HCl:
Molarity = number of moles / Volume in litter
Number of moles = Molarity × Volume in litter
Number of moles = 0.001 mol/L × 0.5 L
Number of moles = 0.0005 mol
percent by mass=(mass of solute/ mass of solution)*100 %
mass of solute=58.5 g
density (H₂O)=1 g/cm³*(1000 cm³/1dm³)=1000 g/dm³
mass of solvent (H₂O)=0.5 dm³ * (1000 g/dm³)=500 g
mass of solution=mass of solvent + mass of solut
mass of solution=58.5 g+500 g=558.5 g
% mass=(58.5 g/558.5 g) * 100%=10.47% of Na.
solution: 10.47% of Na.
Water molecules are made of hydrogen atoms and one oxygen atom.
Hope this helped!