Question

calculate the molality patassium carbonate, which is form by diserveing 2.51g of it in 1 litter solution. (Density of solution 0.85g per ml )​

Answer 1

Answer:

Step-by-step explanation:

Molality or Molal concentration is a measure of the concentration of a solute in a solution given as a ratio of the amount of substance (in moles) in a specified amount of mass of the solvent.  

Formula for Molality is a s follows:

molality = moles of solute / mass of solvent (kg)

Find moles of Potassium carbonate  

molar mass = 138, mass = 2.5

moles  = mass / molar mass  

          = 2.5 / 138

          =  0.01812    

Find mass of the solvent

0.85 g/ml is 0.85kg/liter (conversion factor is 1000)

Therefore 1 liter will have 850g of the solution or 0.85kg

The molality will be:

m = moles of solute/ mass of solvent

          0.01812/ 0.85

       = 0.02132 mol/kg