Chem 103 1st Edition Exam 2 Study Guide Lectures 1 12 Lecture 12 February 23 The unit for molarity is M and is calculated by taking moles over volume To dilute solutions you take a sample of a concentrated solution n moles of the solute and add H2O In water NaCl dissociates which means the atoms split up The Na attracts to O atoms in the H2O and the Cl attracts to H atoms In order to tell if its an electrolyte take these steps If its ionic is it soluble If yes it s a strong electrolyte if no its not one If its molecular and a binary molecular compound or a pure element it s a nonelectrolyte Also a strong acid is a strong electrolyte while a weak acid is a weak electrolyte Lecture 13 February 25 In a solution a strong electrolyte has complete dissociation A weak electrolyte has partial dissociation A nonelectrolyte has no dissociation In order to know if a compound is soluble you simply look at the solubility rules provided A precipitate is an insoluble product of an aqueous reaction Lecture 14 February 27 When handling precipitate reactions and forming the net ionic equation you don t break down the solid only the aqueous compounds Same goes for acid base reactions except you don t break down the liquid Same goes for gas evolution reactions except you don t break down the gas or liquid Lecture 15 February 29 In order to remember if the change in an ion is oxidation is oxidation or reduction remember this OIL RIG Oxidation Involves Loss of electrons while Reduction Involves Gaining electrons In order to predict if a reaction will occur with a solid and liquid use the activity series provided Quantum mechanics were developed in the early 1900 s by many physicists It is based on the ways light interacts with matter Visible light is only one type of electromagnetic radiation There are different types of electromagnetic radiation shown on the electromagnetic spectrum All electromagnetic radiation has particle wave duality Which means that it behaves both like a particle and like a wave Lecture 16 March 4 Electromagnetic radiation can be categorized by wavelength and frequency Wavelength is the distance between 2 equivalent points on a wave Frequency is the number of cycles in a given time The speed of light is calculated by wavelength times frequency There are three experiments that disagree with the statement that light behaves like a wave Blackbody radiation photoelectric effect and atomic emission spectrum The black body radiation one is where dark objects have the tendency to glow when you add energy The photoelectric effect is where high frequency light shined on a metal surface shows that only electrons reflect off The atomic emission spectroscopy is where light from a lamp shone through a prism shows a line spectrum where only specific photons show after while sunlight through a prism shows a rainbow Max Planck describes behavior of light at different temperatures where light travels in bundles and the smallest observable amount of energy is a photon He says that the energy of one photon is equal to Plancks constant times the frequency Niels Bohr made a model for the atom where the nucleus is like a sun while the electrons are different planets orbiting it Lecture 17 March 6 An electron has a certain amount of energy when it occupies an orbit The energy is calculated as 2 18 10 18 n 2 As an electron moves closer to the nucleus it emits energy photon and as it moves further away it absorbs energy photon Only certain energies can be emitted or absorbed DeBrogle wavelength says matter can be a wave if its moving and is calculated by frequency Plancks constant meters speed m s