Question

7.45 grams of KCL s dissolved in 100 grams of water.whaat will be the molality of the solution​

Answer 1

Answer:

1 mole/kg.

Explanation:

Molality is defined as the number of moles of solute present in 1kg of solvent.

and is denoted by m.

Thus, molality(m) = No. of moles of solute / Mass of solvent.

Here, solute is 7.45 grams of KCl and solvent is 100 grams of water = 0.1 kg

GMW of KCl= 39+35.5=74.5g

Moles of KCl:

   74.5 g of KCl    =     1 mole (for any weight)

then,  7.45 g of KCl =        x moles

     x  =7.45 x 1/74.5

     x=0.1 mole.

So,  molality(m) = No. of moles of solute / Mass of solvent

         molality=   0.1/0.1

                      = 1 mole/kg.

(Remember that the numerator part of the formula is moles and not mass)

Hope it helps:)

All the best!!!