You will need
  • - handle;
  • paper for records;
  • calculator.
If you need to calculate the volume percentage content of the substance x, use the formula: CV% = Vx*100/ Vобщ = Vx*100/(Vx+Vy+...+Vn), %;where Vx is the volume of the substance; Vобщ is the total volume, which is the sum of the volumes Vx, Vy,...Vn – component substances.
To calculate the mass percentage of substance x apply the formula:Cm% = Mx*100/Mobs = Mx*100/( Mx+My+...+Mn), %;where Mx – mass of the substance;Mobs is the total mass, which consists of mass Mx, My,...Mn – component substances.
If required to convert volume percentage content in mass, use the relationship: M = V*p, in kg; where M is the mass of matter, kg;V – volume, m3;p – density, kg/m3.
There are challenges to finding the percentage of a component resulting from mixing two solutions with different concentration.For example, you want to determine the mass percentage content of NaCl in solution obtained by mixing 1 liter of a 10% solution and 2 l of a 20% solution. Density of solutions of 1.07 g/cm3 and 1.15 g/cm3, respectively.
To solve find the mass of 1l of 10% solution and 2 l of 20% using the formula from step 3. Translate liters to cm3: 1l = 1000см3. You will receive at 1.07 kg and 2.30 kg. Fold both the masses and get a lot of mixed solution of 1.07+2,30 = 3.37 kg
Converting the formula from step 2, find the mass of NaCl in the first and second solution: Мсоли1 = 1,07*10/100 = 0,107 kg. Мсоли2 = 2,30*20/100 = 0,460 kg. Fold the masses and get a lot of salt in the resulting solution: 0,107+0,460 = 0,567 kg. By the formula from step 2, find the percentage content of salt in the mixture of solutions: 0,567*100/3,370 = 16,83 %.