kg p 981 Previous Answers Submit v Correct kg was either rounded differently or used a different number of significant figures than required for this part. Express your answer with the appropriate units. The high heat of vaporization of water makes it an effective coolant for the human body via evaporation of perspiration, extending the range of temperatures in which humans can exist. Part A What is water's density at 98 C Assume a constant coefficient of volume expansion. This provides stability of temperature for land masses surrounded by water, provides stability for the temperature of the human body, makes it an effective cooling agent, and many other benefits. Water has the highest specific heat of any common substance, 1 calorie/gm ☌ = 4.186 J/gm ☌. The water further expands upon freezing, so that water freezes from the top down, and ice floats on water. This decrease in density is only about one part in 10,000 as it cools from 4☌ to 0☌, but this is sufficient to cause the water near freezing to come to the top. But at about 4☌ it reaches a maximum density and then decreases in density as it approaches the freezing point. Water at ordinary temperatures contracts and increases in density as it is cooled, like most substances. While the hexagonal ice form discussed above is the primary form of ice and is the dominant form from the freezing point at 273K down to about 72 K, 13 different crystalline forms of ice have been idendified according to Debenedetti and Stanley. Solution Verified by Toppr Water has its maximum density of 1g/cm3 or 1000kg/m3 at 4C. This hexagonal lattice contains more space than the liquid state. The expansion upon freezing comes from the fact that water crystallizes into an open hexagonal form. The expansion during the phase change may be shown on a PvT surface, and contrasts with the contraction upon freezing of most substances. Then the further expansion as a part of the phase change keeps the ice floating with some 8% of its mass above the surface. For example, water density at the depth of 10 km (6.2 mi) is 1038 kg/m³. Increasing the pressure always increases the water density. Water density changes with the change of pressure and temperature. It drops to 0.994 g/cm³ at 35 ☌ at the surface. The fact that water reaches a maximum density at about 4☌ causes bodies of water to freeze on the top first. The density of pure water at 4 ☌ at its maximum density is 1 g/cm³. The fact that water expands upon freezing causes icebergs to float. Just above and below 4☌ they are almost the same.The Expansion of Water Upon Freezing The Expansion of Water Upon Freezing See the explanation and the link to the answer on Socratic. The water molecules are slowing down and coming closer together, which increases the density, and the clusters are forming, which decreases the density.

Water samples just above and below 0☌ are very different. The maximum density of water occurs at 4 C because, at this temperature two opposing effects are in balance. At that T, the tendency toward settling into a special low-energy structure runs away in a cooperative manner, and ice crystals form. 4☌ just happens to be the T at which the expansion, due to settling into the special low-energy states, and the contraction, due to the general trend to spend more time in contact at low T, cancel.Ġ☌ is another matter. From Avogadros hypothesis, 1 mole of water 6.02×10²³ molecules. Find the density of water at 4☌ in different units, such as pounds per cubic foot, kilograms per cubic metre, or milligrams per cubic metre. Water has the maximum density of 1g/cm3 only when it is pure water. When the temperature changes from either greater or less than 4 degrees, the density will become less than 1g/cm3. Finally, we shall determine number of molecules of water in the bottle. Water has its maximum density of 1g/cm3 or 1000kg/m3 at 4C. Nothing really special happens there in the structure of the water. Volume of water 499.8 mL Mass of water Mass Density × Volume. At higher T, the molecules sample even higher energy states, and a majority of them are loosely packed, so the liquid expands- the more typical behavior. When things cool, they settle into lower energy arrangements. For most molecules, that typically involves squeezing together a bit, but water happens to have a low-energy arrangement that’s rather open. The expansion of water at lower T results from the water molecules arranging themselves to minimize the energy of their interactions. I assume you are referring to liquid water, not ice, since 4☌ is about the temperature (T) at which liquid water has a minimum volume, at atmospheric pressure.

Density of water at 4c