Convert the volume of water from milliliters to kilograms

Oct 13, 2025 by magicalceylontours.com 40 views

Introduction

In chemistry, a molal solution is a solution that contains a specific number of moles of solute per kilogram of solvent. A 3.5 molal solution of calcium chloride, for example, would contain 3.5 moles of calcium chloride per kilogram of water. In this article, we will explore the concept of molality and how to calculate the mass of calcium chloride needed to make a 3.5 molal solution using 375 mL of water.

Understanding Molality

Molality is a measure of the concentration of a solution, expressed as the number of moles of solute per kilogram of solvent. It is an important concept in chemistry, as it allows us to compare the concentrations of different solutions. The formula for molality is:

M = moles of solute / mass of solvent (in kg)

For example, if we have a solution that contains 3.5 moles of calcium chloride per kilogram of water, the molality of the solution would be 3.5 mol/kg.

Calculating the Mass of Calcium Chloride

To calculate the mass of calcium chloride needed to make a 3.5 molal solution using 375 mL of water, we need to follow these steps:

Convert the volume of water from milliliters to kilograms: Since 1 kilogram of water is equal to 1000 milliliters, we can convert 375 mL of water to kilograms by dividing by 1000.

375 mL / 1000 = 0.375 kg

Calculate the number of moles of calcium chloride needed: Since the solution is 3.5 molal, we need to multiply the mass of water (in kg) by the molality to get the number of moles of calcium chloride needed.

moles of CaCl2 = molality x mass of water (in kg) moles of CaCl2 = 3.5 mol/kg x 0.375 kg moles of CaCl2 = 1.3125 mol

Calculate the mass of calcium chloride needed: To calculate the mass of calcium chloride needed, we need to multiply the number of moles of calcium chloride by its molar mass. The molar mass of calcium chloride is 110.98 g/mol.

mass of CaCl2 = moles of CaCl2 x molar mass of CaCl2 mass of CaCl2 = 1.3125 mol x 110.98 g/mol mass of CaCl2 = 145.35 g

Conclusion

In conclusion, to make a 3.5 molal solution of calcium chloride using 375 mL of water, we need to calculate the mass of calcium chloride needed. By following the steps outlined above, we can determine that we need 145.35 g of calcium chloride.

Frequently Asked Questions

What is molality? Molality is a measure of the concentration of a solution, expressed as the number of moles of solute per kilogram of solvent.
How do I calculate the mass of calcium chloride needed to make a 3.5 molal solution? To calculate the mass of calcium chloride needed, you need to follow the steps outlined above: convert the volume of water from milliliters to kilograms, calculate the number of moles of calcium chloride needed, and calculate the mass of calcium chloride needed.
What is the molar mass of calcium chloride? The molar mass of calcium chloride is 110.98 g/mol.

References

CRC Handbook of Chemistry and Physics
Chemical Society of Japan
American Chemical Society

Additional Resources

Molality Calculator
Calcium Chloride Molar Mass Calculator
Chemistry Tutorials and Resources

Note: The content of this article is for informational purposes only and should not be used as a substitute for professional advice or guidance.

Introduction

In our previous article, we explored the concept of molality and how to calculate the mass of calcium chloride needed to make a 3.5 molal solution using 375 mL of water. In this article, we will answer some of the most frequently asked questions related to molality and calcium chloride solutions.

Q&A

Q: What is molality?

A: Molality is a measure of the concentration of a solution, expressed as the number of moles of solute per kilogram of solvent. It is an important concept in chemistry, as it allows us to compare the concentrations of different solutions.

Q: How do I calculate the mass of calcium chloride needed to make a 3.5 molal solution?

A: To calculate the mass of calcium chloride needed, you need to follow these steps:

Convert the volume of water from milliliters to kilograms.
Calculate the number of moles of calcium chloride needed by multiplying the mass of water (in kg) by the molality.
Calculate the mass of calcium chloride needed by multiplying the number of moles of calcium chloride by its molar mass.

Q: What is the molar mass of calcium chloride?

A: The molar mass of calcium chloride is 110.98 g/mol.

Q: How do I convert the volume of water from milliliters to kilograms?

A: To convert the volume of water from milliliters to kilograms, you can divide the volume in milliliters by 1000. For example, 375 mL of water is equal to 0.375 kg.

Q: What is the difference between molality and molarity?

A: Molality is a measure of the concentration of a solution, expressed as the number of moles of solute per kilogram of solvent. Molarity, on the other hand, is a measure of the concentration of a solution, expressed as the number of moles of solute per liter of solution.

Q: How do I calculate the molarity of a solution?

A: To calculate the molarity of a solution, you need to know the number of moles of solute and the volume of the solution in liters. You can then divide the number of moles of solute by the volume of the solution in liters to get the molarity.

Q: What is the relationship between molality and molarity?

A: The relationship between molality and molarity is that they are both measures of concentration, but they are expressed in different units. Molality is expressed as moles of solute per kilogram of solvent, while molarity is expressed as moles of solute per liter of solution.

Q: How do I calculate the mass of a solute needed to make a solution of a given molality?

A: To calculate the mass of a solute needed to make a solution of a given molality, you need to know the molality of the solution, the mass of the solvent, and the molar mass of the solute. You can then use the formula:

mass of solute = molality x mass of solvent x molar mass of solute

Q: What is the significance of molality in chemistry?

A: Molality is an important concept in chemistry because it allows us to compare the concentrations of different solutions. It is also used to calculate the mass of a solute needed to make a solution of a given molality.

Conclusion

In conclusion, molality is an important concept in chemistry that allows us to compare the concentrations of different solutions. By understanding how to calculate the mass of a solute needed to make a solution of a given molality, we can better understand the properties of solutions and how to prepare them.

Frequently Asked Questions (FAQs)

What is molality? Molality is a measure of the concentration of a solution, expressed as the number of moles of solute per kilogram of solvent.
How do I calculate the mass of calcium chloride needed to make a 3.5 molal solution? To calculate the mass of calcium chloride needed, you need to follow the steps outlined above: convert the volume of water from milliliters to kilograms, calculate the number of moles of calcium chloride needed, and calculate the mass of calcium chloride needed.
What is the molar mass of calcium chloride? The molar mass of calcium chloride is 110.98 g/mol.

References

CRC Handbook of Chemistry and Physics
Chemical Society of Japan
American Chemical Society

Additional Resources

Molality Calculator
Calcium Chloride Molar Mass Calculator
Chemistry Tutorials and Resources

Note: The content of this article is for informational purposes only and should not be used as a substitute for professional advice or guidance.