How to calculate percentage

The concept of the percentage content is used in chemistry, biochemistry, physics, food industry. This is one way to Express the concentration of the component in the total value. If a cent, hundredth of value, the percentage content shows the number of shares.

You will need

• - handle;
• paper for records;
• calculator.

Instruction

1. 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.
2. 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.
3. 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.
4. 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.
5. 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
6. 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 %.