Three clock glasses are inserted under a file camera. A brown paper towel works simply as well. A brown record towel provides better color contrast of the fluid spots and also the rate of evaporation compared to a white paper towel. A autumn of water, a autumn of ethanol, and a autumn of acetone are put on separate watch glasses or in separate locations of the record towel and also the price of evaporation is observed. The autumn of acetone evaporates much much faster than the ethanol which evaporates much faster than the drop of water.

You are watching: What type of liquid evaporates the fastest

Setting the stage prior to doing the demonstration: have actually students predict i m sorry liquid will evaporate fastest and also the slowest. Have students define their choices.

• i m sorry liquid will evaporate the slowest? The fastest? Explain.

What components determine just how fastor sluggish a liquid will evaporate in ~ room temperature?


• that will aid to draw the Lewis frameworks of every molecule,determine if the molecule is polar or non-polar, and also calculate the molecular mass of every compound.
• it will aid to identify the species of intermolecular forces of attraction present between molecules.

Sample student data table

Rate the evaporation versus kind and toughness of IMF

Type of IMFStrength that IMFRelative price of Evaporation
Acetone
Ethanol
Water

Strengths ofIMFsVapor press (kPa) in ~ 20°CMelting allude (°C)
Acetonemedium 28 -95
Ethanolmedium- strong 5.95- 114
Waterstrong 2.33 0.0

Strengths that IMFs
*
Hvap(kJ/mol)
Boiling allude (°C)
Acetonemedium30.3+56.5
Ethanolmedium- strong39.3+78
Waterstrong40.6+100

A collection of Power allude Slides to accompany this show is obtainable in the appropriate menu.


This demo is probably best used when discussing intermolecular forces. College student often think the molecular mass the a compound is the significant factor governing physical properties, such together boiling point and evaporation.

Learning Objectives

1. Identification of intermolecular pressures operating within fluid samples of water, ethanol, and also acetone and also the correlation of a physical property, price of evaporation, v the type and stamin of the IMF in the liquid.


Lead Time
One job of lead time is compelled for this project.
Discussion

Acetone evaporates much much faster than water, also though its molecule mass is more than 3 times together much. Water molecules, in the liquid and solid state, are qualified of hydrogen bonding, whereas a repertoire of acetone molecules in the fluid state do not. The fairly strong hydrogen bonding in between water molecules slows the evaporation rate and increases the surface ar tension, as confirmed by acetone's flatter drop shape on the watch glass. Ethanol exhibits hydrogen bonding between ethanol molecules but does no evaporate as quickly as water.


document camera or overhead projector and screen (for a tool to large lecture hall)three little watch glasses or a brown record towelthree dropper bottles v stoppers or lids, one containing water, one containing ethanol, one containing acetone

The three watch glasses are placed on the overhead projector. A autumn of water, a fall of ethanol, and a fall of acetone are put on separate watch glasses and the price of evaporation is observed. The fall of acetone evaporates much quicker than the autumn of water or the ethanol.

One day of lead time is forced for this project.


Acetone is really flammable. Take appropriate precautions.Potential wellness Effectsof acetone:Inhalation -Inhalation of vapors irritates the respiratory tract tract. May reason coughing, dizziness, dullness, and headache. Greater concentrations can produce main nervous device depression, narcosis, and unconsciousness.Ingestion -Swallowing little amounts is not most likely to produce harmful effects. Sloop down of larger amounts may produce abdominal pain, nausea and also vomiting. Aspiration right into lungs can develop severe lung damage and also is a clinical emergency. Various other symptoms space expected to parallel inhalation.Skin contact -Irritating because of defatting action on skin. Reasons redness, pain, drying and cracking that the skin.Eye Contact:- Vapors space irritating come the eyes. Splashes may reason severe irritation, with stinging, tearing, redness and also pain.Chronic Exposure -Prolonged or repetitive skin call may develop severe wake up or dermatitis.

Ethanol is flammable and can be toxic in quantity.

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Thanks to Dr. JulieHaack, department of Chemistry & Biochemistry, college of Oregon Chemistry Department, for arguing this demo.