Water is a polar molecule and because of its polarity, it may create hydrogen bonds.
- These hydrogen bondings provide water with qualities that are necessary for life on Earth.
Covalent bonds (shared electrons) exist between the oxygen and hydrogen atoms in water.
- %%Oxygen has a high electronegativity (ability to attract electrons), whereas hydrogen has a low electronegativity.%%
- Because of this difference in electronegativity, electrons in the covalent link between oxygen and hydrogen are unequally shared, with electrons spending more time around the oxygen atom.
- As a result, a polar covalent bond is formed with a partial negative charge around the oxygen atom and a partial positive charge around the hydrogen atom, as seen in the image attached.
- As a result, the partial negative charge on an oxygen atom in one water molecule attracts the partial positive charge on a hydrogen atom in another water molecule, forming a hydrogen bond.
- As a result, water molecules are attracted to one another.
Because water molecules can form hydrogen bonds, they have qualities that aid in the survival of life on Earth, such as the image attached above.
- %%Water molecules are "sticky," exhibiting cohesive and adhesive properties.%%
- They are attracted to other water molecules as well as other polar compounds.
- This is what gives water its distinct qualities, such as its high surface tension and ability to do so.
Because of the negative sign in the pH formula, a greater [H+] value results in a lower pH value, and a lower [H+] value results in a higher pH value.
- As a result, a solution with a pH of 3 has a greater [H+] than a solution with a pH of 5.
- @@Furthermore, because the pH scale is logarithmic, a one-unit change in pH translates to a tenfold variation in H+ concentration.@@
A pH of 3 has ten times the H+ concentration of a pH of 4 and one hundred times the concentration of a pH of 5.
- The pH of a water-based solution is determined by the quantity of dissociated water molecules (split into H+ ions and OH– ions) and the relative quantities of these ions.
Pure water will dissociate and create equal amounts of H+ and OH– ions, yielding a pH of 7.
- @@Acids raise the relative concentration of H+ ions in a solution, whereas bases raise the concentration of OH– ions in a solution.@@
- Biological systems can be extremely sensitive to pH fluctuations. Buffers are essential for keeping pH levels in live cells generally constant.
If the pH of a cell falls too low (excess H+), the process will shift to the left, allowing the basic bicarbonate ions to neutralize the excess H+ ions and restore the cell to its original state.
- When the pH of a cell becomes too high (excess OH–), the reaction swings to the right, introducing additional H+ ions into the cell to neutralize the excess OH–, lowering the pH down to normal levels.
- Within a water molecule, oxygen and hydrogen atoms form covalent connections.
- Because oxygen has a higher electronegativity than hydrogen, the electrons in this link are shared unequally, resulting in a polar covalent bond.