Question

KCl is an ionic salt with a formula weight of 74.54 g/mole.

A 1.417 M (mole/liter) KCl solution has a density of 1064.5 grams/liter at 20 ^OC.

Use the Molarity and the formula weight to find the mass (g) of salt in one liter.

Then, find the mass (g and kg) of water in one liter of the solution.    

Determine the molality (m), or moles of salt per kg of water, by dividing the moles of salt in one liter by the kg of water in one liter.

Show all units and use proper significant figures.

KCl is an ionic salt with a formula weight of 74.54 g/mole.

A 1.417 M (mole/liter) KCl solution has a density of 1064.5 grams/liter at 20 ^OC.

Use the Molarity and the formula weight to find the mass (g) of salt in one liter.

Then, find the mass (g and kg) of water in one liter of the solution.    

Determine the molality (m), or moles of salt per kg of water, by dividing the moles of salt in one liter by the kg of water in one liter.

Show all units and use proper significant figures

Answer 1

formula weight = 74.54 g/mole.

molarity = 1.417 M

volume = 1 L

Molarity = moles / volume

1.417 = moles / 1

moles = 1.417

moles = mass / moalr mass

1.417 = mass / 74.54

mass of KCl = 105.6 g   --------------------> answer

solution mass = 1064.5 g

mass of water = 1064.5 - 105.6 = 958.9 g

mass of water = 958.9 g   ------------------> answer

molality = moles of solute / mass of solvent in kg

             = 1.417 / 0.9589

             = 1.48 m

molality = 1.48 m