and Base Theories Until today acids and bases defined in many different ways but first modern description is done by Swedish scientist Svonte ARHENIUS in 1884. He said, Aqueous solutions of acids give H+ ion. For example: NaOH → Na+ + OH−and Aqueous solutions of bases give OH- ion for example NaOH → Na+ + OH− Second description of acids and bases is found by Danish chemist J.N. Bronsted and English chemist in T.N LOWRY in 1923. According to them matter that gives protons are acid and
pH is usually referred to test out or find the measure of a concentration of hydrogen ions. pH is used to measure whether the solution if it is a base or an acid. The term pH stands for power of hydrogen. Usually there is a scale for measuring pH, Solution with a 7 or below is consider an acidic solution, but an pH greater than 7 is consider a base solution, and 7 is a neutral solution. The pH scale is a set of solution standards whose pH is established by the international system. Most of the times
and lesson 07.02 (Acid-Base Reactions). An acid is a substance that produces hydrogen ions, H+ or hydrodium ionsH3O+ in solution. There are three “kinds of acids”: Arrhenius, BrØnsted-Lowry, and Lewis Acid. An Arrhenius acid is a substance the increases the concentration of hydrogen ion, H+ or hydronium ions H3O+when dissolved in water. You must have water. A BrØnsted-Lowry acid is any substance that donates a hydrogen ion, H+ to another substance. A Lewis acid is any substance that accepts a lone
Electrolysis is a chemical reaction caused by electricity in solutions. Electrolysis can separate molecules (like separating water into hydrogen and oxygen gas, which is called electrolysis of water), electroplate a metal, can be used for welding, and can even be used for hair removal. Electrolysis was discovered by Alessandro Volta. The materials to cause electrolysis are a source of direct current (like batteries), electrolyte, and two electrodes. A direct current is current, which electricity
electrons to become negative ions. The FIRST ELECTRON AFFINITY of an element is the ENTHALPY CHANGE WHEN ONE MOLE OF GASEOUS ATOMS GAINS ELECTRONS TO FORM ONE MOLE OF GASEOUS IONS. Electron affinity DECREASES as you DESCEND the group VII: F à 333kJ Cl à 346kJ of energy is released for every one mole of F/Cl/Br/I Br à 324kJ atoms changing to a mole of F/Cl/Br/I ions. I à 295kJ This trend can be explained by the fact that as you descend the group, the X- ion becomes less stable and
The Effect of pH on Enzyme Activity pH is a measure of the concentration of hydrogen ions in a solution. The higher the hydrogen ion concentration, the lower the pH. Most enzymes function efficiently over a narrow pH range. A change in pH above or below this range reduces the rate of enzyme reaction considerably. Changes in pH lead to the breaking of the ionic bonds that hold the tertiary structure of the enzyme in place. The enzyme begins to lose its functional shape, particularly the
more readily. What are electrophiles? Why does benzene only undergo electrophilic but not nucleophilic substitution? By definition, a molecule which forms a covalent bond by accepting a pair of electrons is called an electrophile. Any molecule, ion or atom that is electron deficient in any way can behave as an electrophile. In contrast, any molecule which forms a covalent bond by donating a pair of electrons is called a nucleophile. Nucleophiles are usually rich in electrons and seek out positive
noble gases. This essay is divided into three main sections it will first describe how the ions, ionic, covalent and metallic chemical bonds are formed. It will then go on to explain the types of bonds which can form given the position of the periodic table and the forces required to hold the molecules together. The final part of the essay will define electron pair repulsion theory and the shapes of molecules. Ions are an electrically charged atom formed by the loss or gain of an electron, occurring in
shell. With these interactions of molecules, which are formed by bonds, properties of life emerge. Bonds vary in type, with each having their own specific properties, effects and strengths. These varying types of bonds consist of: covalent, ionic and hydrogen. A covalent bond is the chemical bonding in which the attractive force between atoms is created by the sharing of electrons, resulting in the formation of a cell's molecules and is categorized into two subtypes, non-polar and polar. While a non-polar
Nitrate: Physical Appearance' caption='Ammonium Nitrate: Physical Appearance'}] The chemical formula of ammonium nitrate is NH4NO3: It has two nitrogen (N) atoms, four hydrogen (H) atoms and three oxygen (O) atoms. __Ammonium nitrate__ contains two ions: one ammonium ion (NH4+) and one nitrate ion (NO3)-, so the bond between these two ions is what we call an ionic bond. The structure of the formula
a solution or melt. It is also used to produce alkalis and elements such as chlorine and hydrogen. The process involves the addition (oxidation) or subtraction (reduction) of ions in elements. The electric current motions the ions to proceed onto the electrodes. For example, the cations (positive ions) move to the negative electrode (cathode) and the positive electrode (anode) will receive the negative ions (anions). This process, both regular and vise-versa can only be done with the use of an electrolytic
more time available, ideally I would have preferred to use two alkalis as well as two acids. Predictions First of all, here are the definitions for an acid and an alkali: An acid is a substance that forms hydrogen (H+) ions when placed in water.
minutes, because with lower currents, not much copper was being deposited, so I decided t time for 5 minutes so that all the different masses could have some copper collected. Using 50 ml3 of copper sulphate solution, more ions would be present in the solution so more ions would go to the electrodes and more copper would be formed. In a 100ml3 beaker, more of the electrodes are covered in the solution, so more copper will form quicker. I decided to use these currents, because there are
between metal and non metal atoms. They are formed by the exchange of electrons which forms charged particles called ions. Metal atoms usually use their outer electrons when they react with other substances. This results in a sodium particle which has more protons than electrons. The number of protons remains unchanged. This new particle has a positive charge and is described as a sodium ion. In the sodium atom there is an extra electron provided which may cpmbone with a non metal atom such as chlorine
Properties of Ionic and Covalent Bonds Explained Within the last unit of Chemistry, the cause of ionic and covalent properties was revealed. The true predictor of the compound lies in the bonds that take place. Normally within an ionic bond there is a non-metal and a metal element bonded together. During the bonding elements completely transfer valence electrons between atoms. The metal within the bond loses the few electrons that it has in the outer-most shell which then causes the metal to
conduct electricity when molten or dissolved in water, but not when they are in a solid state as the oppositely charged ions are held together by strong ionic bonds in a giant lattice and this means electricity cannot pass through it and the ions are unable to move. If electrolytes are molten or dissolved in water their ions are free to move, and the movement of ions in liquids is key in electrolysis. Electrolysis takes place in an electrolyte cell. The diagram below shows the apparatus
electron - the 1s orbital [IMAGE]Suppose you had a single hydrogen atom and at a particular instant plotted the position of the one electron. Soon afterwards, you do the same thing, and find that it is in a new position. You have no idea how it got from the first place to the second. You keep on doing this over and over again, and gradually build up a sort of 3D map of the places that the electron is likely to be found. In the hydrogen case, the electron can be found anywhere within a spherical
body fluid. The common cation that being measured are sodium ion and potassium ion, but potassium ion usually not included within the calculation due to very low amount within human body fluid (Emmett and Narins, 1977, pp. 38). The common anions used in the calculation of anion gap are chloride ion and bicarbonate ion. The calculation of anion gap as following: [(Na2+ + K+) − (Cl- + HCO3- )] (Wilson, 2012, p. 907) Usually, potassium ion is not included due to low concentration and stable amount
Alkaline phosphatase, or AP, is an enzyme that is responsible for dephosphorylation, or removing phosphate groups, of various types of molecules such as proteins and nucleotides. It has a molecular weight of 140-160 kilo-Daltons and as said in the name, alkaline phosphatase works in an environment with pH values ranging from 7.5-9.5, which is an alkaline, or basic, environment. And according to Sigma-Aldrich, alkaline phosphatase can be used to “to dephosphorylate the 5'-termini of DNA or RNA to
Bonds: The force of attraction as well as chemical properties in atoms or molecules of elements or compounds contrives three different types of chemical bonds. 1. Ionic Bonding: The bond which generates two oppositely charged ions and the complete transfer of valence electrons is an ionic bond. Metals by losing their outer most electrons they can achieve a noble gas configuration and satisfy their octet rule , similar happens to the non-metals but