The key point is that you should have been able to pile many more drops of water on the penny than drops of alcohol. The explanation here is pretty much identical to the one above. The water molecules have much more cohesion that alcohol molecules, because they grab onto one another through hydrogen bonds.
Why can more drops of water fit on a penny than alcohol?
But alcohol has a different size and shape and has its polar part on one end. 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.
Why number of drops made by water are less than that of ethanol?
Because of the strong attraction between water molecules, the water forms a large “sphere” of water on coin. … This configuration in the molecule produces some hydrogen bonding which is weaker than that in water molecules. As a result, the ethyl alcohol has less surface tension than water.
Why water can hold more drops on the coin?
The cohesive force that occurs between water molecules is so strong that, at the water’s surface, it creates a “skin”, which is known as surface tension. … As drops of water are added onto a penny, the adhesive force between the water and the penny keeps the water from falling off.
Why is water a better solvent than ethanol?
This is because the water is able to form hydrogen bonds with the hydroxyl group in these molecules, and the combined energy of formation of these water-alcohol hydrogen bonds is more than enough to make up for the energy that is lost when the alcohol-alcohol hydrogen bonds are broken up.
How many drops of water will fit on a penny?
Were you surprised to discover that a lot more drops of water fit on a penny than you predicted? We had 27 drops of water on ours! Surface tension and cohesion is the reason you can get so many drops of water on a penny. Cohesion is the “stickiness” of like molecules to one another.
Can a penny hold more drops of plain water or 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 happens when you add a small amount of detergent to a large drop of water?
Adding soap lowers the water’s surface tension so the drop becomes weaker and breaks apart sooner. Making water molecules stick together less is what helps soaps clean dishes and clothes more easily.
Which has higher surface tension water or 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.
Why is salt water less cohesive?
Salt water have less cohesion than distilled water. This is because most of the atoms are already bonded to each other so there are less atoms to be able to let cohesion occur.
Which side of a penny will hold more drops of water choose the best hypothesis?
Choose the best hypothesis. If I use the heads side of a penny, then it will hold more drops of water than tails. Is the penny wet or does it just have water on it? Tails will hold more drops of water.
Why do pennies turn silver in zinc?
When a copper penny is heated in a solution of sodium hydroxide mixed with zinc dust, small amounts of zinc dissolve into the surface of the penny. This causes the penny to look silver since there is now a layer of zinc over the outside of the penny.
What is the shape of the drop of water on the plastic sheet?
Explanation: Surface tension is the name for the attractive forces between the particles or molecules in water, which make the water drops become ball shaped or spherical. This is because the molecules inside a drop are attracted to each other in all directions, from the surface inward.
Is ethanol a stronger solvent than water?
Ethanol therefore attracts non-polar molecules. Thus, ethanol can dissolve both polar and non-polar substances. In industrial and consumer products, ethanol is the second most important solvent after water.
What is the strongest solvent?
Water is called the “universal solvent” because it is capable of dissolving more substances than any other liquid. This is important to every living thing on earth.
Is alcohol a stronger solvent than water?
Alcohols are less polar than water. The alkyl groups have positive inductive effect, so electron density around the oxygen atom is higher compared to that in water. The O-H bond is less polar and hydrogen bonds between the molecules are weaker than in water. On this picture you can see a mixture of water and ethanol.