Explain The Properties Of Water Cohesion

Heat or q of water is determined by the formula q = m x s x ∆ T, and q of the solution is q solution = - q water. In order to calculate ∆H, a calorimeter, an isolated system is used to calculate the heat of a chemical reaction. Using the heat found by the calorimeter, heat (kJ) is divided by the number of moles (n) in order to calculate ∆H of a solution. Enthalpy is used to determine if a system is endothermic or exothermic. If the ∆H of a system is negative then the system will be exothermic.

The purpose of this experiment was to see if a penny could hold more drops of salt water or tap water. It was found that a penny could hold an average of 22.3 drops of tap water and only 20.8 drops of salt water. These results are consistent with the hypothesis: If the salt concentration of water impacts the amount of water a penny holds, then the penny will hold less drops with salt water. While dropping the water onto the penny, it was observed that the water formed into a dome-like shape on the penny. It looked like the individual drops of water turned into one large drop of water. This was observed for both the tap and salt water. This happened due to the cohesion and surface tension of water. Cohesion simply means that water molecules are attracted to each other and want to cling together. Surface tension is the special term that is applied to the cohesion of water molecules.

Attractions between water and other molecules, which is adhesion, is also possible because of the polarity as well. In relation to hydrogen bonds, water’s high specific heat is changed when hydrogen bonds are made or broken. When a hydrogen bond breaks, heat is absorbed whereas when a hydrogen bond forms, heat is released. In addition to HSH, ice is able to float in liquid water because hydrogen bonds in ice is more structured than in water, making the ice less dense. Also, water is a versatile solvent because of its polarity, which helps it form hydrogen bonds (mentioned above). The structure of water molecules also affects the dissociation of water, where H2O breaks into H+ and OH- due to the polarity of the

Attraction between water molecules which allows insects and other objects to float a top the water

When an object falls onto the surface, it has to push the water molecules apart. If the effect of the weight of the object is insufficient to match the attractive forces between molecules in the surface layer, the object will not enter the surface.

The response earned 1 point for providing a role of water in temperature regulation when it describes how

Hydrogen bonds contribute to a property of water called cohesion or the tendency of water molecules to stick together.

Hypothesis: If 3 drops of soap fit on the penny and 9 drops of water fit on the penny, then the cohesion is water molecules are attracted to other water molecules. Surface tension is the name we give to the cohesion of water molecules at the surface of a body of water. Independent Variable: This is the one you're changing in the experiment, so it's the type of solution that you're dropping on the penny.

6. Could this property of water explain why some bugs can walk on water? Explain. Some bugs can walk on the water since the exterior tension admits the insect to walk on the water.

If a pillbug is exposed to water, then it will be attracted to the water.

Clumps together, ability to keep water in its shell and release it as needed to stay moist

(Click Slide) Due to adhesion, capillary action occurs in plants. Water absorbed from the roots sticks to the walls of xylem vessels in plants, and cause an upward motion. Sometimes, you may see that when you wet a paper towel, the water quick travels up the towel. Capillary action occurs when adhesive forces are stronger than cohesive forces.

Water molecules feel different pulls all around them, ones from the molecules on the surface of the water, and the other ones which are closely packed with other water molecules. Water molecules that are below the surface feel a pull from all around them, on the other hand, the water molecules on the surface feel a pull from below them and next to them. The water molecules toward the surface pull together, and form a bubble. This is called water surface tension.

The fact that most small biological molecules dissolve in water is very important because all the chemical reactions that take place in cells do so in aqueous solution. Plants cam only obtain mineral salts in solution and human digestion will only dissolve soluble foods, meaning large starch molecules must be broken down into soluble sugars. Also many organisms living in water spend most of their time underwater, yet they require oxygen to respire, and as water is such a good solvent the required oxygen gas is dissolved in water. Water’s solvent properties also allow it to act as a transport medium for polar solutes for example the movement of minerals to lakes and seas and removal of metabolic wastes such as urea and ammonia in urine. Water’s thermal properties relate to its heat capacity.

When heat is added to a substance, the kinetic energy of individual particles increases, which makes them move faster resulting in a increase in temperature. The more heat that is added per gram of substance, the greater the temperature change. The relationship between the heat added, the mass of a substance, and the temperature change it undergoes is known as the specific heat.