Exothermic reaction

paper to float to the top of a beaker full of H2O2. Enzyme was changed every time – regular, heated or acidified. The second method was measuring the change in pressure during the reaction. This method involved using regular enzyme and then chilled enzyme. The last method was measuring the amount of H2O2 as the reaction progressed; this demonstrated the disappearance of the…

ABSTRACT Within this experiment, the use of a bomb calorimeter was required in order to determine the heat capacity of the system through the combustion of three separate trials of benzoic acid. The resulting heat capacity values for each trial were averaged, with a standard deviation found as well. This was then used to work backwards, for a naphthalene trial, in order to calculate the change in energy (∆U) and the change of enthalpy (∆H). The accepted value for the change in enthalpy of…

The tarnishing of silver is due to a chemical reaction between silver and hydrogen sulfide, producing silver sulfide and hydrogen gas. The balanced chemical equation is 2Ag (s) + H2S (g) → Ag2S (s) + H2. This is a single replacement reaction. This reaction most commonly occurs through contact with hydrogen sulfide in the air - although direct contact with substances that contain sulfur can cause tarnishing. Silver tarnishes very quickly when it is exposed to air that contains high levels of…

For much of human history, salt has been mined from the areas around dry lake beds and in deposits left after ancient seas dried up. These bodies of water all evaporated, leaving their crystallized salt deposits behind. Mined salt is sourced from these deposits. It differs from sea salt in that sea salt is taken from living oceans. While it is usually ground finely for sprinkling onto food as table salt, some of it is kept in a coarse and chunky form that is referred to as rock salt. Rock salt…

2-Bromoheptane + Potassium TertButoxide reaction yielded 3 different products: 1-heptene, Cis-2-heptene and Trans-2-heptene. However, the major product constituent was 1-heptene. Because Potassium TertButoxide is a bulky base, steric hindrance prevents it from attacking a hydrogen on a highly substituted carbon. Consequently, the base attacks a hydrogen on the least substituted carbon (primary carbon). In this case, steric hindrance is reduced and the elimination reaction is faster, so a less…

In this lab, we did four kind of different test, to mimic the chemistry of digestion. The first one was to test for sugar. We used a dropper and measured 2 ml of maltose and 2 ml of benedict’s solution in a pyrex test tube. After, using a test tube holder, we placed the test tube in a boiling water bath and heated for 5 min. After the 5 min, using a test tube holder we removed the test tube from the water bath. We then repeated the same procedure using starch solution instead of maltose. When we…

by the electrophilic carbon of the nitrone, presumably due to both steric and electronic reasons.29a-f The stereoselectivity results from the approach of allyl cyanide on the less hindered face of nitrone 1 (opposite to the isopropyl group), the reaction taking place via a transition state placing the cyanomethyl group away of the spirocyclic nitrone according to an exo-approach (Scheme 1). In 1D NOE experiments with…

the reaction. We then added KMnO4, drop by drop, to see how much hydrogen peroxide remained in the solution, which was our dependent variable. An enzyme is a catalyst, and it has two fundamental characteristics that it is known for. One of these things it that it can increase the rate of a chemical reaction without being changed or destroyed in the reaction. The second is that they don’t alter the chemical equilibrium between the reactants and the products while they speed up the reaction. …

The experiment began with a reaction of a 1cm3 cube of lamb liver and 5mL of hydrogen peroxide solution being put in test tubes in a beaker filled with 10℃ water until the temperatures of the liver and hydrogen peroxide were 10℃ also. The liver was put into a 100mL measuring cylinder and the hydrogen peroxide was also poured in as the timer was started. After twenty seconds, several millilitres of froth had been produced from the chemical concoction. This froth was recorded into a results table,…

Number6. This is known as the ‘goddess’. Start with hands straight over your head in mountain position. Then spread your legs apart and bend them until you can feel your thighs being parallel to the ground. Spread your hands on the both side of your head and lift them up at a ninety- degree angle. Hold onto this position for at least 10 seconds for five rounds. Number7. Stand straight. Now, lean on the left side with your left elbow touching the left knee. Swing your right hand over your head to…