Alcohol molecules can meet at areas where they would not attract as strongly. The water is more attracted to itself than to the metal of the penny. The alcohol is a bit less attracted to itself so it spreads more on the penny.
What happens when you put rubbing alcohol on a penny?
When water is dropped carefully onto the surface of a penny, it can pile up into a dome shape before spilling over the small lip around the penny’s perimeter. Rubbing alcohol can pile up as well, but will spill over before forming a well-rounded dome.
Why can a penny hold a lot of water?
The attraction of water molecules to other substances, like soil or glass, is called adhesion. As drops of water are added onto a penny, the adhesive force between the water and the penny keeps the water from falling off. … That’s why you can make a bigger “pile” of water than of oil or syrup.
Why is isopropyl alcohol less polar than water?
In the molecule of water the bonds are attached in such a way that the dipoles of oxygen-hydrogen bonds add constructively. Due to the difference in electronegativity of oxygen and hydrogen this molecule is much more polar. That’s why isopropyl alcohol is less polar than water.
Why is water more cohesive than alcohol?
The water molecules have much more cohesion that alcohol molecules, because they grab onto one another through hydrogen bonds. Because a sphere allows for the maximum number of connections between water molecules, the expanding drop of water continues to maintain that shape.
How many drops of alcohol can a penny hold?
About 20 to 30 drops of ethyl alcohol can be placed on a coin depending on drop size.
How many drops of water can a penny hold?
The results indicate that when you drop water on a penny that the heads side of the penny will hold more drops (heads 23 drops, tails 18 drops).
Why does a penny hold more water than soapy water?
You should find that plain tap water produces a much larger, stable drop of water on top of the penny than the soapy water does. This is because plain tap water has higher surface tension, so the surface is “stronger” and can hold together a larger drop.
What caused the water to spill over?
When we fill the glass with water, we notice right away that it can go over the brim of the glass without spilling. This is because of surface tension. … Gravity is pulling on too many of the molecules for their attraction to keep them up, and the water spills down the side of the glass.
Why does water stick to your skin?
First, ‘cohesion’: the attraction of water molecules to each other. This comes from the opposing electric charges on the hydrogen and oxygen atoms of neighbouring H2O molecules. And it’s this mutual attraction of water molecules in the damp layer on the skin that creates the feeling of stickiness.
What makes water more polar than alcohol?
Aren’t both alcohol and water polar molecules? Water is much more polar than an alcohol because the latter has an organic part and a non-organic part (OH) to the molecule. That is why when the alkyl group of an alcohol gets larger it becomes more likely to dissolve organic substances (and the opposite applies.
Why does isopropyl alcohol evaporate faster than water?
As alcohol evaporates at a much faster rate compared with water due to its lower boiling temperature (82 compared to 100 degrees C), it is able to carry away more heat from the skin. This means for a given amount of time much more alcohol evaporates than water.
Is alcohol more polar than water?
The difference in polarity between water and alcohol can also explain another property of these liquids. Since alcohol is less polar than water, alcohol evaporates faster than water and boils at a lower temperature.
Why does water rise higher than alcohol?
Water has greater degrees of hydrogen-bonding in the bulk liquid. … Therefore, since water molecules on a liquid surface are harder to push down on the surface tension is higher for water than for ethyl alcohol.
Does water have stronger intermolecular forces than alcohol?
Water had the strongest intermolecular forces and evaporated most slowly. The strength of the intermolecular forces in isopropyl alcohol are in between water and acetone, but probably closer to acetone because the water took much longer to evaporate.
Why does water have stronger intermolecular forces than isopropyl alcohol?
Isopropyl alcohol is a polar covalent molecule with hydrogen bonding as the predominant intermolecular force. Since the melting and boiling point of isopropyl alcohol is lower than that of water, the hydrogen bonding in it is weaker than that in water.