Reviewer Chemistry Exam PDF

Lesson \#1: Introduction to Energy - Sources of Energy - Renewable - can never be exhausted. - Solar, wind, tidal, agricultural residue, and animal dung - Non-renewable - does not replenish. - Coal, crude oil, natural gas, and uranium -...

Lesson \#1: Introduction to Energy - Sources of Energy - Renewable - can never be exhausted. - Solar, wind, tidal, agricultural residue, and animal dung - Non-renewable - does not replenish. - Coal, crude oil, natural gas, and uranium - Forms of Energy - Chemical energy - Released in chemical reaction, often in the form of heat - Electrical energy - One of the most common and valuable forms of energy - Kinetic energy - The energy of an object that it possesses due to its motion. - Mechanical energy - Often in the form of kinetic and potential energy or work - Nuclear energy - Trapped inside each atom / can be produced by fusion or fission - Thermal energy - Energy-related to temperature - Gravitational energy - ​​​​​​​The energy held by an object in a gravitational field - Second Law of Thermodynamics - States that as energy is transferred or transformed, more and more is wasted - Units of Energy - Work - W = F∆d = ma∆d - m = mass in kg - a = acceleration in ms\^-2 - ∆d = displacement in m - W = (kg)(ms\^-2)(m) = N x m = Joule - 1 Joule = 1 N m = 1 Pa m\^3 - 1 cal = 4.1858 joules - 1 BTU (British thermal unit) = 1055 joules = 252 cal - Related Terminologies - Adiabatic system - thermally insulated system where no heat can flow into or out of the system - Closed system - No matter enters or leaves the system, but the system can exchange energy (in the form of work or heat) with surroundings - Endothermic process - the surroundings are hotter than the system - Exothermic process - the system is hotter than the surroundings - Isolated system - Neither matter nor energy is exchanged with the surroundings - Open system - Matter and energy can be exchanged with the surroundings - Surroundings - everything else, apart from the system - System - that part of the universe under study - Universe - the system plus the surroundings Lesson \#2: Electrochemical Energy - Zeroth law of thermodynamics - State that if two bodies are each in thermal equilibrium with a third body, they are also in equilibrium with each other - Work - W = F∆d (by motion) - W = -P∆V (by expansion) - Heat capacity - The amount of heat required to change the temperature of a given amount of matter by 1°C - Specific heat - The heat capacity of 1 gram of a substance is called its specific heat capacity - Formula - q = mc∆T - q = heat - m = mass - c = heat capacity - ∆T = change in temperature - Enthalpy - H = U + PV - Heat of reaction - endothermic reaction - breaking of reactants - more energy needed - forming of products - less energy released - exothermic reaction - breaking of reactants - less energy needed - forming of products - more energy released - Hess Law - The enthalpy change for any process is independent of the particular way the process is carried out - -  - Energy and stoichiometry - Diagram of a substance Description automatically generated -  Lesson \#3: Electrochemistry - Electrochemistry - study of the interchange of chemical and electrical energy - Galvanic cell - a device in which chemical energy is changed to electrical energy - Electrolytic cell - uses electrical energy to produce chemical change - Redox reaction - Because the metals have lost electrons to oxygen, they have been oxidized; oxidation is therefore the loss of electrons. Conversely, because the oxygen atoms have gained electrons, they have been reduced, so reduction is the gain of electrons. - Corrosion - process through which metals in manufactured states return to their natural oxidation states - Types of corrosion - Galvanic corrosion - the most common and impactful form of corrosion - occurs when two different metals are in contact in the presence of an electrolyte - Pitting corrosion - accelerated corrosion in certain areas rather than uniform corrosion throughout the piece - Microbial corrosion - commonly referred to as microbiologically influenced corrosion (MIC) is caused by microorganisms - When oxygen is absent, sulfate-reducing bacteria are active and produce hydrogen sulfide causing sulfide stress cracking - High-temperature corrosion - deterioration of a metal due to heating - Crevice corrosion - occurs in confined spaces where access of fluid from the environment is limited - corrosion prevention - barrier methods - paint - oil - electroplating - sacrificial method - a more electrochemically active metal is electrically attached to a less active metal - Insight into batteries - Types of batteries - Non-rechargeable - The reaction inside the battery is irreversible - Rechargeable - The reaction inside the battery is reversible Lesson \#4: Nuclear Energy - Nuclear energy - a form of energy released from the nucleus, the core of atoms, made up of protons and neutrons - can be release in two ways - fusion - when nuclei fuse together - fission - when nuclei of atoms split into several parts - Radioactive decay - Gravitational force - acts between all objects having mass - Electromagnetism - responsible for the repulsion of like and the attraction of unlike electric charges - Strong nuclear force - strong force acts between quarks, the constituents of all subatomic particles, including protons and neutrons - Weak nuclear force - manifests itself in certain forms of radioactive decay and in the nuclear reactions that fuel the Sun and other stars - Chemical reaction vs Nuclear reaction - Chemical reaction - involve only a rearrangement of electrons and do not involve changes in the nuclei - Nuclear reaction - involve a change in an atom\'s nucleus, usually producing a different element - Isotopes - are members of a family of an element that all have the same number of protons but different numbers of neutrons - Transmutation - When the number of protons in the nucleus of an atom changes - Nuclear stability - means that the nucleus of an element is stable and thus it does not decay spontaneously emitting any kind of radioactivity - radioactive decay - involves the spontaneous transformation of one element into another - The only way that this can happen is by changing the number of protons in the nucleus - Nuclear Transmutation - Different kinds of Transmutation - Alpha decay - A diagram of a nuclear reaction Description automatically generated - Beta particles -  - Gamma decay - A diagram of a cell Description automatically generated - Penetrating power - Alpha particles can be blocked by a few pieces of paper - Beta particles pass through paper but are stopped by aluminum foil - Gamma rays are the most difficult to stop and require concrete, lead, or other heavy shielding to block them - Level of risk in health - Alpha particles are the most harmful internal hazard as compared with gamma rays and beta particles - Gamma rays are the most harmful external hazard - Beta particles most harmful external can partially penetrate skin, causing "beta burns" - Gamma and x-rays can pass through a person damaging cells in their path - The kinetics of radioactive decay - Rate constant - r = k\[N\] - r = rate decay - k = first order rate constant - N = amount of radioisotope - The rate of decay is often referred to as the activity of the isotope and is often measured in Curies (Ci), one curie = 3.700 x 1010 atoms that decay/second. By knowing the amount of radioisotope and the activity of the sample, the rate constant can be determined - Calculations using first-order rate equation - ln(N/No) = -kt - N = final amount of radioisotope - No = initial amount of radioisotope - k = rate constant - t = time Lesson \#5: Crystallography - Crystallography - arrangement and bonding of atoms, forming geometric patterns and structure of crystal lattices - Arrangement of atoms/molecules can be described as: - Crystalline - arrangement of atoms/molecules forms geometric structures - Amorpous - arrangement of atoms/molecules with no definite pattern - Terminologies - Crystal - Periodic arrangement of atoms in a given space - Lattice - Arrangement of any particles that forms a crystal - Unit cell - The smallest part of crystal that is repeated throughout the whole crystal - Atomic radius - Radius of participating atoms in a crystalline structure - Unit cell length - Length of one-unit cell edge - Atomic packing factor (APF) - determines the percentage of the total volume that the atoms occupy in a given structure - Unit cell structures - Simple cubic - Each corner of the unit cell is defined by a lattice point at which an atom, ion, or molecule can be found in the crystal - Bode-centered cubic (BCC) - unit cell can be imagined as a cube with an atom on each corner, and an atom in the cube\'s center - Face-centered cubic - contains the same particles in the centers of the six faces of the unit cell, for a total of 14 identical lattice point - hexagonal close-packed - the closest packing of spheres in two dimensions has hexagonal symmetry where every sphere has six nearest neighbors - density calculations - p = nAW / VcNa - p = g/cm\^3 - n = \# of atoms / unit cell - AW = g/mol - Vc = cm\^3 / unit cell - Na = atoms or molecules / mol - APF = nVsphere / Vc - Vsphere = cm\^3 / atom -  Lesson \#6: Ideal Gas Processes - Ideal Gas - PV = nRT - P = pressure - V = volume - n = \# of atoms - R = universal gas constant (8.314 J / mol x K) - T = temperature - Heat capacities - A white rectangular object with black text Description automatically generated -