Why is it so difficult to extract drinkable water from seawater? Doooh—stupid second law of thermodynamics!

In the 1960s, there seemed a sweet solution to all of the “shortages” that vex our demon-haunted, fear-first age of technological timidity. You build the nuclear power plants on the seacoast, using the effectively infinite heat sink of the deep ocean as the cold sink (avoiding the need for those scary cooling towers!). In addition to generating electricity too cheap to meter for the power grid, the thermal energy, which would otherwise go to waste, is used to desalinate sea water, which supplies abundant fresh water for human consumption, agriculture, and the adjacent Fission Falls Water Park. Part of the fresh water and electricity is input to the electrolysis plant, which generates hydrogen for mobile transportation applications. The brine-rich by-product of desalination which isn’t sold as artisanal Captain Neutron nuclear sea salt is disposed of by dilution in the deep ocean.

Any territory, however small and seemingly resource-poor, with a modest ocean coastline, could become an energy, agriculture, and transport superpower if only they could tunnel through the fear barrier. New Hampshire has 21 km of Atlantic coastline, which advocates of Porcxit 4 might bear in mind.

Structure of Water and Ice

Water is a covalent compound. It consists of two hydrogen atoms covalently bonded with the oxygen atom at the centre. In water molecule, the central atom goes SP3 hybridization. According to VSEPR theory, it should have tetrahedral structure but the presence of two lone pair of electron in oxygen increases the repulsion between the H atoms and its shape becomes distorted tetrahedral. The HOH bond angle decreases from 109.5o to 104.5o.

Due to the strong electronegative character of oxygen, water molecule is highly polarized. Therefore, there is a formation of intermolecular hydrogen bonding between oxygen of one molecule and hydrogen of another molecule. The extra energy is required to break this molecular bond. Due to this strong association between the hydrogen and oxygen, water molecules become liquid and solid at room temperature. In the absence of hydrogen bond, water would be in gaseous state as that of H2S. This is the reason for H2O being liquid at room temperature while H2S is gas at same temperature while both of the compounds have similar bonding. This is also the reason for anomalous behaviour of water.

Scientist studied that water molecules in ice are arranged in such a way that they form open cage like structure with vacant space due to hydrogen bonding as shown in figure below. With the vacant space, the volume of ice increases. So, as volume has inverse relation with density. Ice has lesser density in compared to water and hence float in water. The figure above shows the arrangement of molecules in ice and water respectively.

Fake chemical atomic structures

Calculate how much salt must be added to water to get a brine with a certain concentration. Please enter two quantities, the third quantity and the concentration will be calculated. A sodium chloride (common salt) solution can have a concentration of up to 36%, for other salts, other values apply.

This page looks at the reactions of the Group 2 elements - beryllium, magnesium, calcium, strontium and barium - with air or oxygen. It explains why it is difficult to observe many tidy patterns.