Plaque is made up of food debris, saliva and the bacteria that are normally present in the mouth, and convert food into acids. It contains acids which, over time, can dissolve away the protective, hard enamel coating of the tooth, and create holes, or cavities.
Many heart diseases are related to bacterial infection. The bacteria reaches the heart through the blood stream, and the starting point is through your gums. Decaying teeth lead to damaged gums provide a way for bacteria to invade the inner body.
Application of equilibrium
Application of EquilibriumBy: Stephanie, Shawna, and Amber
Increased Risk Factors of Tooth Decay• Eating a diet rich in sugar and starch• Sticky foods – more likely to remain on the surface of the teeth.• Snacking increases how long and how often acids are in contact with the teeth.
Tooth Decay• The bacteria in your mouth consumes sugar from the food you eat and produces acids.• Some acids attach to your teeth and form plaque, which coats the teeth and traps the acids next to the surfaces. The acids slowly dissolve the hard enamel surface of the teeth.
Equilibrium Equation• Enamel is composed of a strong, insoluble mineral called hydroxyapatite, Ca5(PO4)3OH.• The equilibrium equation is: – Ca5 (PO4 )3 OH(s) 5Ca 2+ (aq) + OH - (aq) + 3PO4 3- (aq)
Dynamic Equilibrium• Equilibrium exists when two opposing reactions occur at the same time and rate.• The forward and reverse reactions may occur at different rates.• In childrens teeth, mineralization usually occurs faster than demineralization.• In adults, the processes may take place at about the same rate-equilibrium.• However, if the acid becomes highly concentrated at a specific point on a tooth, demineralization occurs, leading to a cavity.
Tooth decay and Le Chatelier’s Principle• 1. Ca5(PO4)3OH(s) 5Ca2+(aq) + 3PO43-(aq) + OH- (aq) Add sugar…• 2. Bacteria + sugar acid (H+)• 3. H+ + OH- H2O• OH- formed by the dissociation of enamel (rxn. 1) reacts with the acid (rxn. 3). This causes the concentration of OH- to decrease and according to Le Chatelier’s principle, rxn 1 will shift right to form more OH-.• Further dissociation of Ca5(PO4)3OH(s) will occur resulting in tooth decay• The more acidity in your mouth, the greater chance for tooth decay
Chemistry of the Blood• Oxygen is transported around the body in blood by the complex molecule hemoglobin, a globular protein which has a central iron atom.• When hemoglobin reacts with oxygen, oxyhemoglobin is formed.• The oxygenation of blood is an equilibrium reaction.• Carbon monoxide, CO, also readily reacts with hemoglobin which can result in carbon monoxide poisoning.
Dynamic Equilibrium• A dynamic equilibrium exists once a reversible reaction ceases to change its ratio of reactants/products, but substances move between the chemicals at an equal rate, meaning there is no net change.• Hb(aq) + CO(aq) -> HbCO(aq) OR• Hb4(aq) + 4CO(aq)-> Hb4(CO)4(aq)
Stress of Equilibrium• The equilibrium constant for this reaction is very large, so there is very little hemoglobin left to react with oxygen. The cells in the body will be starved of oxygen because carbon monoxide rather than oxygen is being transported.• Because the equilibrium constant for the carbon monoxide reaction is so large, low concentrations of carbon monoxide can be harmful.• Because the reaction is reversible, carbon monoxide poisoning can be counteracted, if caught earlier enough, just by providing sufficient oxygen.
Le Chateliers Principle• When a system at equilibrium is disturbed, the equilibrium position will shift in the direction which tends to minimize, or counteract, the effect of the disturbance.• Oxygen VS. Carbon Monoxide, however unless substantial amounts of Oxygen are added, the Carbon Monoxide will not be counteracted.
What Can Produce CO?• Older motor vehicles• Gasoline powered tools• Heaters• Cooking equipment• Tobacco smoke• Concentrations of 100 ppm or higher can negatively effect human health.
Effects on HumansConcentration Symptoms Headache and dizziness within six to35 ppm (0.0035%) eight hours of constant exposure100 ppm (0.01%) Slight headache in two to three hours Slight headache within two to three200 ppm (0.02%) hours; loss of judgment Frontal headache within one to two400 ppm (0.04%) hours Dizziness, nausea, and convulsions800 ppm (0.08%) within 45 min; insensible within 2 hours Headache, dizziness, and nausea within1,600 ppm (0.16%) 20 min; death in less than 2 hours Headache, dizziness and nausea in five3,200 ppm (0.32%) to ten minutes. Death within 30 minutes. Headache and dizziness in one to two minutes. Convulsions, respiratory6,400 ppm (0.64%) arrest, and death in less than 20 minutes. Unconsciousness after 2–3 breaths.12,800 ppm (1.28%) Death in less than three minutes.
Effect on Environment• Carbon monoxide can affect the amount of other greenhouse gases, which are linked to climate change.• Very high levels of carbon monoxide will cause the same problems for birds and animals that are experienced by humans, although these levels are unlikely to be experienced in the environment, except in extreme events such as bushfires.• The Clean Air Act requires EPA to set national air quality standards for specific harmful pollutants.
Chlorofluorocarbons and Ozone Depletion Shawna Rivedal
• Chlorofluorocarbons: Any of various halocarbon compounds consisting of carbon, hydrogen, chlorine, and fluorine, once used widely as aerosol propellants and refrigerants• Ozone: a colorless, odorless reactive gas comprised of three oxygen atoms – Found naturally in the earth’s stratosphere by electric discharges – Absorbs the UV component of incoming solar radiation (harmful to life on earth)
Dynamic Equilibrium• Free radicals react with oxygen molecules to form ozone• Absorption of energy light radiation also triggers decomposition of ozone• Dynamic equilibrium of formation/destruction + + O - - O O O O O
• CFC molecules: – CFCl3 or CF2Cl2 – Carbon, Fluorine, Chlorine • Extremely stable: able to slowly travel from troposphere to atmosphere – Energetic photons break down the CFC molecules: • Cl- able to destroy ozone
Ozone Destroying Cycle of Cl- atoms• Cl + O3 → ClO + O2• ClO + O → Cl + O2• O3 + O → 2O2 – (O3=ozone) – Cl- is a catalyst • Initiates breakdown of ozone to form two O2 molecules NO2 + O2 NO + O3
Stresses on Equilibrium• Increase in (O) – Result: • Shift toward production of ozone – To keep Kc constant• Catalyst• Reduction in Ptotal• Increase in temperature – Exothermic reaction – Ozone (O3) likely to decompose back into O2
Le Chatelier’s Principle• With increased pressure: – Shifts equilibrium towards reactants to reduce increase of heat• With decreased Ptotal : – Shifts equilibrium towards reactants • B/c more gas molecules to help increase pressure
Effect on Environment• Hole in ozone would lead to detrimental, biological impacts – Increased UV exposure • Damaged early development • Increased risk of cancer: – Animal skin, eyes, and immune systems – Impaired plant growth – Reduced plankton production • Are the foundation of aquatic food webs