# What is the KF of lauric acid?

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Lauric acid (the solvent in this experiment) has a reported Kf = 3.9 °C·kg/mol = 3.9 °C/m. In this experiment, you will determine the freezing point of the pure solvent, CH3(CH2)10COOH (lauric acid).

In this regard, what is the van't Hoff factor for lauric acid?

Lauric acid, CH3(CH2)10COOH, is also known as dodecanoic acid and has a van't Hoff factor (i) of 1. To perform this determination, you must know the mass of both the solvent and solute and the molecular mass of the solute. This will allow you to calculate the colligative molality of the solution, mc.

Subsequently, question is, what is KF in freezing point depression? Kf is the molal freezing point depression constant of the solvent (1.86 °C/m for water). m = molality = moles of solute per kilogram of solvent.

Furthermore, what is the molality of lauric acid?

The Kf Value For Lauric Acid Is 3.9°C•kg/mol.

What is the KF of acetic acid?

The density of acetic acid is 1.049 g/mL and Kf (acetic acid) = 3.90 °C· kg/mol The density of the unknown is 0.791 g/mL.

Professional

## Can the van't Hoff factor ever be zero?

The Vant Hoff factor(generally denoted by “i”) gives us an idea of how many molecules or compounds are actually present after dissolving a compund. As molecules cant vanish after dissociation(law of conservation of mass) the molecules existing as solute can never be 0. hence i can never be 0.

Professional

## Why is the van't Hoff factor lower than expected?

Because it breaks up into three ions, its van't Hoff factor is 3. At concentrations greater than 0.001 M, there are enough interactions between ions of opposite charge that the net concentration of the ions is less than expected—sometimes significantly. The actual van't Hoff factor is thus less than the ideal one.

Explainer

## Can the van't Hoff factor be a decimal?

The van't Hoff factor will often (and practically always) come in decimal. Let's take the example of acetic acid which has the chemical formula CH3COOH. This is a weak electrolyte and will partially dissociate in an aqueous solution. The van't Hoff factor will often (and practically always) come in decimal.

Explainer

## What is lauric acid used for?

It is also used for preventing the transmission of HIV from mothers to children. Other uses for lauric acid include treatment of bronchitis, gonorrhea, yeast infections, chlamydia, intestinal infections caused by a parasite called Giardia lamblia, and ringworm. In foods, lauric acid is used as a vegetable shortening.

Explainer

43.2 °C

Pundit

## How do you find the freezing point of lauric acid?

the freezing-point depression follows a simple direct proportionality relationship: ∆Tf = Kf·m (1) where the proportionality constant, Kf, is called the molal freezing-point depression constant. Lauric acid (the solvent in this experiment) has a reported Kf = 3.9 °C·kg/mol = 3.9 °C/m.

Pundit

## How do you calculate freezing point depression?

Strategy:
1. Step 1: Calculate the freezing point depression of benzene. Tf = (Freezing point of pure solvent) - (Freezing point of solution)
2. Step 2 : Calculate the molal concentration of the solution. molality = moles of solute / kg of solvent.
3. Step 3: Calculate Kf of the solution. Tf = (Kf) (m)

Pundit

## What is Molality formula?

The formula for molality is m = moles of solute / kilograms of solvent. In problem solving involving molality, we sometimes need to use additional formulas to get to the final answer. One formula we need to be aware of is the formula for density, which is d = m / v, where d is density, m is mass and v is volume.

Pundit

1 moles

Pundit

## How do I calculate moles?

Use the molecular formula to find the molar mass; to obtain the number of moles, divide the mass of compound by the molar mass of the compound expressed in grams.

Teacher

## What is Colligative property in chemistry?

In chemistry, colligative properties are properties of solutions that depend on the ratio of the number of solute particles to the number of solvent molecules in a solution, and not on the nature of the chemical species present. The word colligative is derived from the Latin colligatus meaning bound together.

Teacher

## At what temperature does lauric acid become a solid?

The melting point of lauric acid is 44 °C. Applications, Question 4). 2. The freezing point of lauric acid is 44 °C, based on the plateau observed at this temperature on the graph.

Teacher

## Is benzoic acid soluble in water?

Benzoic Acid. Benzoic acid or benzene-carbonic-acid is a monobasic aromatic acid, moderately strong, white crystalline powder, very soluble in alcohol, ether, and benzene, but poorly soluble in water (0.3 g of benzoic acid in 100 g of water at 20 °C).

Teacher

## Does the experimental value of KF depend on the amount of benzoic acid used?

Yes, the experimental value of Kf depend on the amount of benzoic acid used.

Reviewer

## How can the KF value of a solvent be determined?

To calculate the freezing point depression constant, or Kf, you'll need the equation: delta Tf = Kfcm where cm is the molal concentration of the solution. Divide the freezing point depression by the molal concentration so you have: Kf = delta Tf / cm.

Reviewer

## How do you find experimental molar mass?

Step 1: List the known quantities and plan the problem. to calculate the molality of the solution. Then use the molality equation to calculate the moles of solute. Then divide the grams of solute by the moles to determine the molar mass.

Reviewer

## How is freezing point depression used in real life?

Freezing Point Depression in Everyday Life
When salt is put on an icy road, the salt mixes with a small amount of liquid water to prevent melting ice from re-freezing. If you mix salt and ice in a bowl or bag, the same process makes the ice colder, which means it can be used for making ice cream.

Reviewer

## What lowers water's freezing point?

Salt lowers the freezing/melting point of water, so in both cases the idea is to take advantage of the lower melting point. Ice forms when the temperature of water reaches 32 degrees Fahrenheit (0 degrees Celsius).

Supporter

## Is freezing point depression negative?

The change in the freezing point is proportional to the amount of solute added. This phenomenon is called freezing point depression. The change in the freezing point is defined as: ∆Tf = Tf,solution − Tf,solvent. ∆Tf is negative because the temperature of the solution is lower than that of the pure solvent.

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#### EveryThingWhat Staff Editor

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25th February, 2020

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