# Temperature and pressure relationship for water

### Pressure, temperature, and volume relation in liquids | Physics Forums

vapor pressure of ice and water over various temperature relationship between pressure (atm) and temperature (K). A well-known result from statistical mechanics is the ideal gas law, PV=nRT which comes in a variety of forms. Here, ndenotes the amount of gas, R is a constant. The boiling point of a substance is the temperature at which the vapor pressure of the liquid For example, water boils at °C ( °F) at sea level, but at ° C ( °F) at 1, metres (6, ft) altitude. . Saturation pressure and saturation temperature have a direct relationship: as saturation pressure is increased.

For example let us say a liquid in a horizontal pipe is under double the static pressure than it was originally. By static pressure I do not mean hydrostatic - I mean static as in the other pressure factor of water not sure what it is called.

### thermodynamics - Water pressure vs temperature - Physics Stack Exchange

Your water company decides, whelp, let's increase the city water pressure! Say originally we had a horizontal copper pipe full of water.

At the one end of the pipe is a tap that is closed.

At the other end of the pipe is the incoming city water company city pressure. Water temperature is 20 degrees celsius room temp in the pipe originally, and a pressure of "1". Then the city increases water pressure to "2".

## Pressure, temperature, and volume relation in liquids

The units do not matter, just say the pressure doubled. The water did not move, because the tap was shut.

Air pressure and temperature demo

Another factor that affects the normal boiling point of a compound is the polarity of its molecules. As the polarity of a compound's molecules increases, its normal boiling point increases, other factors being equal. Closely related is the ability of a molecule to form hydrogen bonds in the liquid statewhich makes it harder for molecules to leave the liquid state and thus increases the normal boiling point of the compound. Simple carboxylic acids dimerize by forming hydrogen bonds between molecules.

A minor factor affecting boiling points is the shape of a molecule.

Making the shape of a molecule more compact tends to lower the normal boiling point slightly compared to an equivalent molecule with more surface area.

Comparison of butane isomer boiling points Common name. The extrapolated density at zero T and P is 1. Densities of water tend towards a 6th power law dependent on temperature and pressure As this power law does not obey the rule of thumb that candidate power laws should exhibit an approximately linear relationship on a log-log plot over at least two orders of magnitude in both the x-axes and y-axes [ ], it seems likely that this relationship is purely empirical.

I am again grateful to Frank Grimer for pointing me at this relationship. Volume change increases as the square-root 3 power of the temperature The square-root 3 term is related to the Vesica Piscesbeing the ratio of the long to short diameter of intersecting expanded icosahedral water clusters the short diameter being the distance between the centers of neighboring dodecahedra and the long diameter associated with a plane of water molecules between the two pentameric boxes Figure 3h joining them.

### PRESSURE AND TEMPERATURE RELATIONSHIP

I am again grateful to Frank Grimer for showing me this relationship. Log10 T-T0 vs log viscosity data In the graph above, H2O values are shown by the green squares red lineand D2O values are indicated by the blue diamonds blue line. As this power law does not quite obey the rule of thumb that candidate power laws should exhibit an approximately linear relationship on a log-log plot over at least two orders of magnitude in both the x-axes and y-axes [ ], it seems possible that this relationship is curious but purely empirical.