Chemical Structure Of Hydrogen Bonds

Water (H2O) is a good solvent because it is partially polarized. The hydrogen ends of the water molecule have a partial positive charge, and the oxygen end of the molecule has a partial negative charge. This is because the oxygen atom holds on more tightly to the electrons it shares with the hydrogen atoms. The partial charges make it possible for water molecules to arrange themselves around charged atoms (ions) in solution, like the sodium (Na+) and chloride (Cl−) ions that dissociate when table salt dissolves in water.

For example, molecules with projecting Hydrogen atoms bond with molecules with projecting Hydroxyl groups (-OH), forming water. The water molecule then leaves the reactants, allowing them to bond to form a larger, more complex molecule.

Hydrogen bonds contribute to a property of water called cohesion or the tendency of water molecules to stick together.

Substance A and B were weighed; Substance A weighed 0.502 g and substance B weighed 0.503 g. Both substances were put into two different test tube with approximately 8 ml of DI water into the test tub. Substance A and B were stirred and B dissolved while A did not. This shows that B is soluble in water compared to A. Thus, shows that B is soluble in water than A. The reason why B is soluble in water is because it has a higher dipole moment than A. With a higher dipole moment, it shows that it is soluble in water since it is polar and the bonds were easily broken.

1) Water molecule is formed with 2 hydrogens and one oxygen atom. Water molecule is a polar molecule because both the opposite side of the molecule have opposite charges. And also, atoms are linked by covalent bonds.

(Click Slide) Another unique property of water is its high specific heat capacity. Due to the strong hydrogen bonds that exist between water molecules, a lot of energy is needed to break down the bonds. As the Particle Theory states, particles move faster and further apart when heated. This is why water helps maintains a moderate temperature on Earth and different bodies of water, crucial for the survival of organisms.

By identifying the solubility of the unknown, it could lead to a closer interpretation as to what the functional group the unknown may be. Solubility is determined based on intermolecular attractive forces, such as hydrogen bonding, dipole-dipole, and London dispersion forces. Intermolecular attractive forces arise due to different electron environments in different molecules. For example, water molecules are good at dissolving

Ionic and Covalent Bonding Ionic and covalent bonding is involved when the atoms of an element chemically combine to make their outer shells full and to make the atoms stable. The first type of bonding you can get is ionic bonding. Electrons are transferred from one atom to another to try and create full outer shells, this gain and loss of electrons on the atoms results in positive and negative ions. In these compounds you get electrostatic force, this is the force/attraction that occurs between the positive and negative ions that hold the compound together.

Put hydrogen bonds, dispersion forces and dipole-dipole forces in order of how strong they are and give an example of each

Water is a polar molecule made up of on atom of hydrogen and two atoms of

Intermolecular forces hold molecules together when they are in solid or liquid state. However, water has the ability to dissociate many salts and ionic compounds. This is called dissolving. When NaCl is added to water, it dissociates into the ions; Na+ and Cl- . The positive sodium ions are surrounded by the slightly negatively charged part of water molecules (i.e. oxygen) in the water molecules and the negative chlorine ions are surrounded by the slightly positively charged part of water molecules (i.e. the hydrogen). The kinetic energy of the sodium chloride molecules increase with temperature. This destabilizes the solid state that it is currently in. This increased motion means that the molecules are less able to hold together and as such they dissolve at faster rates and larger amounts.

The fact that most small biological molecules dissolve in water is very important because all the chemical reactions that take place in cells do so in aqueous solution. Plants cam only obtain mineral salts in solution and human digestion will only dissolve soluble foods, meaning large starch molecules must be broken down into soluble sugars. Also many organisms living in water spend most of their time underwater, yet they require oxygen to respire, and as water is such a good solvent the required oxygen gas is dissolved in water. Water’s solvent properties also allow it to act as a transport medium for polar solutes for example the movement of minerals to lakes and seas and removal of metabolic wastes such as urea and ammonia in urine. Water’s thermal properties relate to its heat capacity.

For example hydrogen chloride, the chlorine within the HCl molecule is more electronegative than the hydrogen, and as a result the electron are attracted closer to the chlorine than the hydrogen atom. Between these hydrogen chloride molecules exist dipole-dipole interactions and as a result the dipoles can interact with each other and increase the boiling point.

Water molecules have a strong bond to each other because of the polarity of the molecule. One side is very positive and the other very negative. It is difficult to move or break these bonds because the positive is attracted to the negative. So what does that have to do with specific heat? The answer is that water has such a high specific heat because it is a polar liquid.

As the bonds and the attractive forces are so strong, the water molecules cannot break them, like they do with NaCl. The polar water and the silicon and oxygen molecules are not attracted because although the silicon and oxygen bonds are polar, the compound contains four silicon and oxygen bonds which cancels the separation of the two charges (the dipole) this causes the non-polarity in the structure and why when put into water, it does not dissolve ("Electronegativity: Why