Basic Chemistry PDF

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Notes on learning objectives for Basic Chemistry...

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Basic Chemistry Matter - Object occupying space, has matter Mass - The amount of matter in an object Atom - smallest particle of an element made of subatomic particles Element - simplest type of matter made of multiple of one type of atom Molecule - two or more atoms combined to form a structure that behaves as an independent unit. Compound - a substance (molecule or ionic bond) made of two or more different types of atoms Atomic structure - Protons (+) and neutrons (neutral) make up the middle of an atom. Electrons (-) in surrounding electron shells shell - 2 in inner shell, 8 in valance (outer) shell. Full electron shells = inert (stable) Not full = Chemically reactive Protons (+) define the element (one proton = Hydrogen, 18=oxygen etc) Neutrons and electrons can change, protons can't. Atomic number = # of protons in (neutral) atom Mass number = # of protons + # of neutrons in nucleus Isotope = different version of atom (atom with different # of neutrons) (different mass) Atomic Mass = average mass of its naturally occurring isotopes Avogadro’s number = 6.022 × 1023 1 mole ("mol") = 6.022 × 1023 number of entities Molar mass = mass of 1 mole of a substance expressed in grams Chemical Bonding Ionic bond - atoms transfer electrons -> atoms turn into ions = particle with net electric charge [+/-]  Cations = Positively charged  Anions = Negatively charged Covalent bond - atoms share electron pairs, atoms form a molecule. (single [2 x e-]/double[4 x e-] covalent bond etc)  Nonpolar CvBs = both e- shared equally  Polar CvBs = e- not shared equally Hydrogen Bonds - positively charged H of one molecule is attracted to the negatively charged O, N, or Fl of another molecule, a hydrogen bond forms. Like ionic bonds, but weaker, no exchange of electrons.

Chemical reactions & the formulae used to describe them Synthesis Reaction - two or more reactants chemically combine to form a new and larger product.  Dehydration reactions - Synthesis reactions in which water is a product Decomposition Reaction - larger reactant is chemically broken down into two or more smaller products.  Hydrolysis Reactions Those where water is split into two parts Anabolism - Sum of all Synthesis reactions in the body Catabolism - Sum of all Decomposition reactions in the body Metabolism - Sum of all anabolic and catabolic reactions in the body. Reversible Reaction - Products can be converted back to the original reactants. Equilibrium = Rate of product formation is equal to the rate of the reverse reaction Oxidation-reduction reactions - Atom partially or completely loses an electron and another atom gains that electron (ionic or covalent bond)  Oxidation = loss of an electron by an atom OIL  Reduction = gain of an electron. RIG Energy = capacity to do work Potential energy is stored energy Kinetic energy - energy that is actually doing work Mechanical energy results from the position or movement of objects Chemical energy - potential energy stored within the chemical bonds of a substance Heat energy - energy that flows from a hotter object to a cooler object Activation energy - minimum amount of energy that the reactants must have to start a chemical reaction Catalysts - Substances that increase the rate of chemical reactions without being permanently changed or depleted themselves Enzymes - Proteins that act as catalysts -> increase rate of chemical reactions by lowering the activation energy necessary for the reaction 4 most common elements in humans:  Oxygen  Carbon  Hydrogen  Nitrogen Electrolytes, Solutes & Concentrations Mixture - combination of two or more substances physically blended together, but not chemically combined. Solution -A solution is any liquid, gas, or solid in which the substances are uniformly distributed, with no clear boundary between the substances. The solute dissolves in the solvent Suspension - a mixture containing materials that separate from each other unless they are continually, physically blended together. Colloid - mixture in which a dispersed substance is unevenly distributed throughout the mixture, do not settle.

2 x Solution concentration expressions: 1. indicate the percent of solute by weight per volume (%) of solution. A 10% solution of sodium chloride can be made by dissolving 10 g of sodium chloride into enough water to make 100 mL of solution. 2. osmole, which contains Avogadro’s number (6.022 × 1023) of particles (i.e., atoms, ions, or molecules) in 1 kilogram of water. A milliosmole is 1/1000 of an osmole. Molarity Calculations (#M required x combined atomic mass g x mL required) divided by 1000 ml/L E.g. How many grams of NaCl would be required to produce a 1 M solution with a volume of 1.0 L? Show workings. Na 22.99 + Cl 35.45 = 58.44. (1M x 58.44g x 1000 ml) / 1000ml/L = 58.44g/mol How many grams of HCl would be required to produce a 2 M solution with a volume of 100ml? Show workings. H 1.01 + Cl 35.45 = 36.46 (2M x 36.46g x 100ml) /1000ml/L = 7.292g/mol How many grams of CaCl2 would be required to produce a 0.5 M solution with a volume of 3.0 L? Show workings. Ca 40.08 + (Cl 35.45x2) = 110.98. (0.5M x 110.98g x 3000ml) /1000ml/L = 166.47g/mol Osmosis 

Diffusion of water through a selectively permeable (allows water but not all the solutes dissolved in the water to diffuse through it) membrane from a less concentrated solution (fewer solutes, more water) into the more concentrated solution (more solutes, less water).  Osmosis is important to cells because large volume changes caused by water movement disrupt normal cell function. Osmotic pressure is the force required to prevent water from moving by osmosis across a selectively permeable membrane. isosmotic - Solutions with the same concentration of solute particles hyperosmotic - Solution with a greater concentration of solute particles hyposmotic - Solution with a lesser concentration of solute Isotonic solution -in which cell neither shrinks nor swells Hypertonic solution - in which cell shrinks (crenation) Hypotonic solution - in which cell swells (lysis) Electrolytes - Cations and anions that dissociate(separate) in water (can conduct an electric current)  functions hydration, regulating osmotic pressure, controlling blood pH, ensuring the proper function of muscles and nerves. Regulation - Homeostatic mechanisms  Organs (kidneys, liver, skin, and lungs) remove them from the body.  The concentrations of electrolytes in the extracellular fluid are regulated, so that they do not change unless the individual is growing, gaining weight, or losing weight. o Sodium (Na) - Excess excreted by kidneys, also through sweat. Aldosterone increases Na+ reabsorption in kidney, ^ Na+ in the

ECF --> ^ Antidiuretic hormone (ADH)secretion --> ^ water reabsorption in the kidneys & ^ thirst.  Hypernatremia - Thirst restlessness, convulsions, High BP  Hyponatremia - Lethargy, seizures, coma o Potassium (K) - Maintained in narrow range, affect resting membrane potentials, Aldosterone increases amount secreted  Hyperkalaemia - increased neuromuscular irritability, restlessness  Hypokalaemia - decreased neuromuscular excitability, weakness. o Magnesium - Excess lost in urine, limited capacity of kidneys to reabsorb, decreased levels = ^ reabsorption. o Phosphate - increase in plasma phosphate increases amount of phosphate in nephron beyond that which can be reabsorbed; excess is lost in urine  Hypophosphataemia: reduced absorption from intestine due to vitamin D deficiency or alcohol abuse.  Hyperphosphataemia: renal failure, chemotherapy, hyperparathyroidism (secondary to elevated plasma calcium levels) Properties of water - a polar molecule composed of one atom of oxygen and two atoms of hydrogen.  High specific heat, water is good at stabilizing body temperature, protecting against friction and trauma, making chemical reactions possible - dehydration and hydrolysis reactions, and serves as a mixing medium Acid - a proton donor (substance that releases H+) Base - a proton acceptor (substance that binds to )(accepts) H+ ) A strong acid or base almost completely dissociates in water. A weak acid or base partially dissociates. What usually occurs when an acid and base of equal strength are mixed? The acid and base neutralize each other, and the acidic and basic properties are no longer present pH =7 How does pH affect enzyme function? Each enzyme has an optimum pH range. Changing the pH outside of this range will slow enzyme activity. Extreme pH values can cause enzymes to denature Buffer - A buffer is a solution that resists changes of pH when acids or bases are added to the solution (Regulates pH) Important biological buffers  Bicarbonate  Phosphates  Protein  Respiratory and renal mechanisms

pH scale - shows the H+ concentrations of various solutions.  A neutral solution has an equal number of H+and OH− and is assigned a pH of 7.  Acidic solutions, in which the number of H+ is greater than the number of OH−, have pH values less than 7.  Basic, or alkaline, solutions have more OH− than H+ and a pH greater than 7. pH affects the human body  The normal pH range for human blood is 7.35 to 7.45.  Acidosis results if blood pH drops below 7.35, in which case the nervous system becomes depressed and the individual may become disoriented and possibly comatose.  Alkalosis results if blood pH rises above 7.45. Then the nervous system becomes overexcitable, and the individual may become extremely nervous or have convulsions. Both acidosis and alkalosis can be fatal....