Assuming that the solute consists entirely of nacl (over 90% is), calculate the osmotic pressure of seawater at 20∘c.

The osmotic pressure of seawater at 20∘c. = 3.12 atm

Osmotic pressure is the minimum pressure applied to the solution so that there is no osmotic transfer from a thinner solution to a more concentrated solution.

General formula:

π = osmosis pressure (atm)

M = concentration of solution (mol / l)

R = constant = 0.08205 L atm mol-1 K-1

T = Temperature (Kelvin)

The full question should be:

Seawater contains 3.8g of salts for every liter of solution.

Assuming that the solute consists entirely of NaCl (over 90% is), calculates the osmotic pressure of seawater at 20 degrees Celsius.

mole NaCl = 3.8 gram: 58.5 (molar mass of NaCl)

mole NaCl = 0.065

so the molarity = 0.065 M

For NaCl electrolyte solutions, the van't Hoff factor (i) is taken into account. And the value of i for strong electrolytes such as NaCl which has a degree of ionization = 1 then i = n = 2 (NaCl ionizes into 2 ions namely Na + and Cl-)

Temperature = 20° C+ 273 = 293 K

then

π = M. R. T. i

π = 0.065. 0.082. 293. 2

π = 3.12 atm

colligative properties

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Raoult's law

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The vapor pressure of benzene

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The freezing point of a solution

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Keywords: osmotic pressure, electrolyte solution

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).