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Molarity of H2SO4 is 18 M. It’s density is 1.8g/cm3, hence molality is?
By BYJU'S Exam Prep
Updated on: September 25th, 2023
The molarity of H2SO4 is 18 M. Its density is 1.8g/cm3, hence molality is 500 mol/kg. Steps to Calculate the molality:
We know that 1ml=1cm3
- molarity = mol H2SO4/ L solution
- molality = mol H2SO4/ kg solvent
Using density,
- Mass of the solution = 1.8 g/ml x 1000 ml = 1800 g
- Molecular weight of H2SO4 = 98g
- Mass of solute (H2SO4) = 18 mol x 98 g = 1764 g
- Mass of solvent = mass of solution – mass of solute
Substituting the values we get:
= 1800 g – 1764 g
On simplifying:
= 36 g = 0.036 kg
Molality = mol H2SO4/ kg solvent
Substituting the values we get:
= 18 mol/0.036kg
On simplifying:
= 500 mol/kg
Molarity
The total number of moles of solute in a given solution’s molarity is expressed as moles of solute per litre of solution. As opposed to mass, which fluctuates with changes in the system’s physical circumstances, the volume of a solution depends on changes in the system’s physical conditions, such as pressure and temperature. M, sometimes known as a molar, stands for molarity. When one gramme of solute dissolves in one litre of solution, the solution has a molarity of one. Since the solvent and solute combine to form a solution in a solution, the total volume of the solution is measured.
One of the crucial characteristics of solutions is molality. It is mostly based on the mass of the solvent and is used to express the concentration of a solute in a solution. The terms molality and molal concentration are both used occasionally. The letter m is typically used to represent it.
Molality was primarily defined in terms of its relationship to molarity, which is defined as the molar concentration of a solution. The first mention of this property’s use is in a 1923 publication by G. N. Lewis and M. Randall. The book Thermodynamics and the Free Energies of Chemical Substances discussed the subject.
Summary:
Molarity of H2SO4 is 18 M. It’s density is 1.8g/cm3, hence molality is?
The molarity of H2SO4 is 18 M. Its density is 1.8g/cm3, hence molality is 500 mol/kg. The total moles of solute in a solution given molarity is shown as moles of solute per litre of solution.
