How do you find the molar mass of a volatile liquid?

How do you find the molar mass of a volatile liquid?

number of moles = n = pV/RT . But we go one step further, because we will also measure the mass of the evaporated liquid. Knowing the mass and the number of moles will allow us to compute the molar mass of the liquid: molar mass = (mass)/(number of moles).

Why do volatile liquids with lower boiling points give better results?

Volatile liquids have low boiling points. A liquid with a low boiling point will begin to boil faster than liquids with higher boiling points. Much less energy (in the form of heat) is required to break the intermolecular bonds of a volatile liquid than those of liquids having higher boiling points.

What does a volatile liquid mean?

A volatile substance can be defined as (1) a substance that evaporates readily at normal temperatures and/or (2) one that has a measurable vapor pressure. The term volatile usually applies to liquids. The rate at which a substance vaporizes (volatilizes) under a fixed set of conditions is called the evaporation rate.

What is the most accurate way of measuring the molar mass of a volatile compound?

The Dumas method of analysis can provide a fairly accurate determination of molar mass. V is the volume in liters of the vessel in which the liquid is vaporized and T is the temperature in kelvins of the vapor.

How do intermolecular forces affect volatility?

Substances with strong intermolecular forces have lower vapor pressures and are less volatile, while substances with weak intermolecular forces have higher vapor pressures and are more volatile.

Why do volatile liquids have high vapor pressure?

As the temperature of a liquid increases, the kinetic energy of its molecules also increases. As the kinetic energy of the molecules increases, the number of molecules transitioning into a vapor also increases, thereby increasing the vapor pressure.

How are volatile substances affected by surface conditions?

At a given temperature a more volatile substance will more readily turn to gas as the molecules escape from the surface, such as solvents and paint, shown in Figure 1. Thus the more volatile a substance is, the lower vapour pressure it has.

What does highly volatile mean?

adjective. A situation that is volatile is likely to change suddenly and unexpectedly.

What is the main source of error in the determination of the molar mass?

The primary source of error is in the mass measurement, which had a standard deviation of 1.5%. The method could be improved by using a more precise balance to decrease the error in the mass measurements. It is also interesting to note that the molar mass was found to be slightly smaller than the literature value.

How does molar mass affect volatility?

Molecular weight In general, volatility tends to decrease with increasing molecular mass because larger molecules can participate in more intermolecular bonding, although other factors such as structure and polarity play a significant role.

What makes a liquid volatile?

A substance is said to be volatile if it boils at a low temperature, changing from the liquid to the gas phase. Substances that are gases at room temperature are extremely volatile: they have high volatility. They can only be seen as liquids when exposed to low temperatures or high pressures.