A SHORT HISTORY OF THE COST PER DEFECT METRIC Version 1.1. May 5‚ 2009 Abstract The oldest metric for software quality economic study is that of “cost per defect.” While there may be earlier uses‚ the metric was certainly used within IBM by the late 1960’s for software; and probably as early as 1950’s for hardware. As commonly calculated the cost-per-defect metric measures the hours associated with defect repairs and the numbers of defects repaired and then multiplies the results
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SN1 Reactions For SN1 reactions it’s important to have a good leaving group because this reaction occurs in two steps. Because alcohol is such a poor leaving group it needs to be helped by silver nitrate to help promote the ionization of the alkyl halide. This helps form the products of the SN1 reaction. 2-chlorobutane This reaction didn’t occur because the carbocation isn’t stable enough for an SN1 reaction. 2-bromobutane This reaction occurred in 32 seconds. This reaction occurred quickly
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Title Experiment 17 Reaction Kinetics- Determination of the Activation Energy of the Reaction Between Oxalic Acid and Potassium Permanganate. Objective To determine the activation energy of the reaction between oxalic acid and potassium permanganate. Theory and Background Activation energy is the minimum amount of energy that is required to activate atoms or molecules to a condition in which they can undergo chemical transformation or physical transport. In terms of the transition-state
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The light reactions of photosynthesis contain two photosystems‚ two electron transport chains‚ and ATP synthase. These parts are embedded in the thylakoid membranes of a chloroplast. The photosystems contain a collection of chlorophyll molecules. Chlorophyll‚ which is the green pigment of leaves‚ absorbs light energy that excites electrons to a higher energy level. Energized electrons from photosystem I are passed down an electron transport chain and added to NADP+ to form NADPH. Electrons from photosystem
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RATE OF REACTIONS. The reaction rate (rate of reaction) or speed of reaction for a reactant or product in a particular reaction is intuitively defined as how fast or slow a reaction takes place. For example‚ the oxidative rusting of iron under the atmosphere is a slow reaction that can take many years‚ but the combustion of cellulose in a fire is a reaction that takes place in fractions of a second (right). Chemical kinetics is the part of physical chemistry that studies reaction rates. The concepts
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rate of reaction (mol dm-3 s-1) for the following chemical reaction: CaCO3(s) + HCl(aq) CaCl2(s) + H2O(l) + CO2(g) Research question: How does altering concentration (mol dm-3) of hydrochloric acid (HCl) affect the rate of reaction (g/s) for the following reaction: CaCO3(s) + HCl(aq) CaCl2(s) + H2O(l) + CO2(g) Background information: The reaction between calcium carbonate and hydrochloric acid is an example of a neutralization reaction between an acid and a base. Neutralization reactions involve
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Polymerization reaCTIONS polymers are high-molecular-weight compounds‚ fashioned by the aggregation of many smaller molecules called monomers. Ex. plastics that have so changed society and the natural and synthetic fibers used in clothing are polymers. Classification of polymers Homopolymers - consist of repeated long chains or structures of the same monomer unit. Ex. PVC(polyvinyl chloride) Copolymers - polymers that consist of more than one molecule. Trimers - molecules consisting
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metals arranged in order of their reactivity based on displacement reactions‚ reduction of their oxides by hydrogen or carbon‚ the relative ease of decomposition of their compounds and reactions with oxygen‚ dilute acids and water. The higher up a metal is in the reactivity series‚ the more reactive it is. In the experiment conducted‚ the three metals‚ magnesium‚ zinc and copper each had to undergo displacement reactions and reactions with water‚ oxygen and dilute acids‚ to arrange them in the order
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endothermic reaction happened everywhere around us. Basically exothermic and endothermic reaction is transfer energy to the surroundings and take in energy from the surroundings (BBC GCSE bitesize). If the reaction forward ，then is exothermic.If the reaction is the backwards ‚then is endothermic. When a reaction take place‚ the energy started to transfer from different object to the surroundings or take away energy from the surroundings. When temperature started to change. Exothermic Reaction An exothermic
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The Effect of pH on Enzymatic Reaction Rate Abstract Enzymes are affected by changes in pH. The most favorable pH value— the point where the enzyme is most active—is known as the optimum pH. This experiment was conducted to determine the effect of pH reaction rate on an enzyme‚ catalase‚ from yeast. The experimental results indicate that the catalase worked best at a neutral pH level of seven (7). Introduction An enzyme is a protein molecule that serves as a catalyst. “The basic function of
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