Enter the mole fraction in the vapor and the mole fraction in the liquid into the calculator to determine the K Value. This calculator can also determine either mole fraction if the other values are known.

## K Value Formula

The following formula is used to calculate a k value.

K = y / x
• Where K is the K value, or vapor-liquid equilibrium ratio.
• y is the mole fraction in the vapor
• x is the mole fraction in the liquid

To calculate a k-value, divide the mole fraction in the vapor by the mole fraction in the liquid.

## K Value Definition

The K value is most often called the vapor-liquid equilibrium constant. It’s a ratio of the mole fraction in vapor to the mole fraction in a liquid of vapor to liquid transition or state. This value is derived from Henry’s Law and is sometimes called Henry’s constant.

## Can K values be negative?

In chemistry, as the formula above is used for, k values cannot be negative since you cannot have a negative mole fraction of a substance.

## K Value Example

how to calculate k value?

1. First, determine the mole fraction in the vapor.

Determine the mole fraction of the molecule in a vapor state.

2. Next, determine the mole fraction in the liquid.

Calculate the mole fraction of the molecule in a liquid state.

3. Finally, calculate the K Value.

Calculate the K value using the formula above.

## FAQ

What is a mole fraction?

A mole fraction is the ratio of the number of moles of one component of a solution to the total moles of all components.