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A 2.40 M aqueous solution of LiCl has a density of 1.0538 g/mL. If the total mass of the solution is 54.0 g, what masses of solute and solvent are present?

Respuesta :

anfabba15

Answer:

5.21 g of solute (LiCl)

48.79 g of solvent (water)

Explanation:

This is our information

[LiCl] = 2.40 M → 2.40 moles of salt in 1L of solution

Density of solution: 1.0538 g/mL (solution mass / solution volume)

54 g → solution mass

Let's determine solution volume with density

1.0538 g/mL = solution mass / solution volume

1.0538 g/mL = 54 g / solution volume

Solution volume = 54 g / 1.0538 g/mL → 51.2 mL

Now, we can know the mass of solute, by molarity.

In 1 L of solution (1000 mL) we know that we have 2.40 mol of chloride.

Then, how many moles of chloride, do we have in 51.2mL of solution. We make a rule of three:

1000 mL has 2.40 moles of LiCl

51.2 mL would have (51.2 . 2.40)/1000 = 0.123 moles of solute

We apply molar mass to know the mass ( mol . molar mass)

0.123 moles .  42.39 g/m = 5.21 g of LiCl

Finally solute mass + solvent mass = solution mass

5.21 g LiCl + solvent mass = 54 g

54 g - 5.21 g = solvent mass → 48.79 g

mickymike92

The mass of solute is 5.22 g and the mass of solvent is 48.78 g

Molarity, Volume and Density relationship

  • Molarity = moles/volume
  • Density = mass/volume
  • moles = mass/molar mass

Molarity of LiCl = 2.40 M

Therefore, 2.40 moles of salt is present in 1L of solution

Density of solution: 1.0538 g/mL

Mass of solution = 54.0 g

  • Volume of solution = mass/density

Volume = 54 g / 1.0538 g/mL

Volume of solution = 51.2 mL

  • Number of moles of LiCl present in 51.2 mL solution is determined;

1 L or 1000 mL solution contains 2.40 moles

51.2 mL will contain 51.2 * 2.4 mole/1000

Number of moles of LiCl present in 51.2 mL solution = 0.123 moles

  • mass of solute is determined

Using mass = number of moles * molar mass  

molar mass of LiCl = 42.5 g

mass of LiCl = 0.123 * 42.5 g

mass of LiCl = 5.22 g of LiCl

  • Total mass of solution = mass of solute + mass of solvent

mass of solvent = solution mass - mass of solute

mass of solvent = 54.0 g - 5.22 g

mass of solvent = 48.78

5.21 g LiCl + solvent mass = 54 g

Therefore, the mass of solute is 5.22 g and the mass of solvent is 48.78 g

Learn more about mass of solutions, solutes and solvent at: https://brainly.com/question/16757650

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