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 can you add more drops of water than alcohol?
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 do water drops stay on a penny?
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.
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.
Which coin held more water droplets and why?
Observations and results
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.
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 is the appearance of the drops of the liquid using alcohol?
The alcohol and water mixture would look transparent because the alcohol dissolves in water, thus, it became a homogenous mixture. 2. The appearance of the water and cooking oil mixture is that, the cooking oil is above the water and vice versa.
How many drops of h20 can fit on a penny?
STEP 2: Use an eyedropper or pipette to pick up and carefully drip one drop of water at a time onto the penny. STEP 3: Count how many drops you can fit onto one penny until the water overflows. We were able to get ours up to about 27!
Does Soap make water wetter?
In any case, and according to Evan, “Soap reduces the surface tension of water, allowing it to spread more easily.” In effect, it makes the water wetter, and therefore, more effective. …
How do the two droplets behave?
The reason for this chasing behavior is the difference in surface tension of the two droplets. Lower-surface-tension droplets (droplets with higher concentration of food color) will chase the drop with higher surface tension (droplets that have lower food-coloring concentration).
How many drops of soapy water can fit on a penny?
Soapy water had the least surface tension. We were only able to get 11 drops of soapy water on the penny.
What liquid has the strongest surface tension?
Besides mercury, water has the highest surface tension for all liquids, which is due to the hydrogen bonding in water molecules. The surface tension of water causes water molecules at the surface of the liquid (in contact with air) to hold closely together, forming an invisible film.
What happened to the drop of water when you touched it with toothpick?
Why does it work? Water molecules have a strong attraction for each other. This force is strong enough to make the water move towards the water on the toothpick. But when you dip the toothpick into dish soap, the water water is repelled, not attracted, so the water bubble bursts as it tries to move away.
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.
Can coins hold water?
Because water molecules at the surface of the water puddle attract more to one other than they do to the air molecules above them, they cling together and form a dome shape on the coin. … You can keep adding water drops until the surface tension is not strong enough to counter the gravitational pull on the water.
What did you observe when dropping water onto the coin?
Water’s cohesion and surface tension are special because of hydrogen bonds. … The cohesion and surface tension of water becomes apparent when the drops of water you add to the penny reach the penny’s edge. Once the water has reached the edge, you begin to see a bubble or dome of water forming on top of the penny.