Biol 1001 CH6

Biol 1001 CH6 - Handout for Chapter 6 Physical Properties...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
Handout for Chapter 6 Physical Properties of Seawater · Definition of 1 gram (weight unit in metric system): weight of 1 cm 3 of pure water at 3.98 o C (maximum weight of pure water). · Water is very dense compared to air . Thus, any object placed at deep depths in the ocean, will be subjected to tremendous pressure. Every 10 m depth increase corresponds to 1 kg/cm 2 increase in pres- sure (14.22 lbs/in 2 , 1 atmospheric pressure). At the bottom of Mariana Trench, pressure would be 1.1 ton/cm 2 (7.821 ton/in 2 )! · Three states of water: solid (ice), liquid (liquid water), and gas (water vapor). · Water molecules in ice are held together by hydrogen bonds. When some of the hydrogen bonds are broken (by adding heat), ice melts. As more heat is added, more and more hydrogen bonds are broken, and temperature of liquid water rises. When all the hydrogen bonds are broken, it becomes water vapor. · Freezing temperature of pure water is 0 o C and boiling temperature of pure water is 100 o C. · 1 cm 3 of pure water weighs 1 gram at 3.98 o C. · One calorie is the amount of heat required to raise the temperature of 1 gram of pure water by 1 o C. This is called specific heat (heat required to raise the temperature of 1 gram of a substance by 1 o C). · Pure water has a density maximum at 3.98 o C , and a typical sea water has a density maximum near -2 o C (minus 2 o C, freezing temperature of a typical sea water). The density of seawater increases with increas- ing salinity, and it decreases with increasing temperature. · Sensible heat (heat whose gain or loss can be detectable by temperature change) and latent heat (heat whose gain or loss can not be detectable by temperature change). · For water, the latent heat of evaporation is larger (540 calories per gram) than the latent heat of melt- ing (80 calories per gram). Water molecules in ice are held together by hydrogen bonds. Density of ice at 0 o C is 0.917 g/cm 3 (i. e., ice floats in water. 91.7% of ice floating in water is submerged below water surface). When ice melts, some of the hydrogen bonds are broken. When water evaporates, all the re- maining hydrogen bonds are broken. When evaporation (precipitation) takes place at the sea surface, there is a heat transfer (540 calories per gram) from ocean to atmosphere (from atmosphere to ocean). When sea ice forms (melts) at the sea surface, there is a heat transfer (80 calories per gram) from ocean to atmosphere (from atmosphere to ocean). · Salinity of a typical (average) sea water is close to 35 oo / o . · Viscosity
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 4

Biol 1001 CH6 - Handout for Chapter 6 Physical Properties...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online