Enthalpy Calculator Online (Physical Properties Calculator )

We can calculate the physical properties such as:

1. Temperature
2. Pressure
   
3. density
   
4. Enthalpy
5. Internal energy
   
6. Gibbs Free Energy
   
7. Entropy
   
8. Molecular Weight
   
9. Gas Constant
10. Heat Specific
11. Gamma
    

The temperature range 273 K to 5000 K online. you can do by clicking on the Physical Properties page on the online block in the Chemistry Index, or you can visit the web page Physical Properties Online Calculator.
For each reaction specie, the thermodynamic functions specific heat, enthalpy and entropy as functions of temperature are given in the form of least squares coefficients as follows:

Cp/R = A1 + A2T + A3T² + A4T³ + A5T⁴

H/(R*T) = A1 + A2T/2 + A3T²/3 + A4T³/4 + A5T⁴/5 + A6/T

S/R = A1lnT + A2T + A3T²/2 + A4T³/3 + A5T⁴/4 + A7

or

S/R = A1lnT + A2T + A3T²/2 + A4T³/3 + A5T⁴/4 + A7 - lnp

For each specie, two sets of coefficients are included for two adjecent temperature intervals, 273 to 1,000 [K] and 1,000 to 5,000 [K]. The data have been constrained to be equal at 1,000 [K].

Also,

U = H - p*v*MW or U = H - R*T

G = H - S*T

and

u = h - p*v or u = h - R*T/MW

g = h - s*T

Water Softening

Hardness in water is caused by certain salts. The main hardness causing ions are Calcium (Ca²⁺), Magnesium (Mg²⁺) and Bicarbonate (HCO₃^-). These ions or minerals are normally addressed as scale in the water causing scaling of pipes and equipment in drinking water and process water systems.
Softening units offer a water purification solution for hard water and lime scale removal.

In many applications, e.g. the preparation of drinking water, water in breweries and sodas, but also cooling water and boiler feed water, the hardness of the water is of importance.

The hardness is normally measured in German degree, French Hardness or (equivalent) concentration Ca²⁺. Softeners are specific ion exchangers which are designed to remove ions with a multiple positive charge.

Lenntech offers water softeners and related equipment for households, laboratories and industrial applications.

Water softener units are automatically regenerated with salt (NaCl).

Brackish water softeners are also available using specific resins and regenerated with HCl and NaOH.

By : www.lenntech.com