In this experiment, the amount of energy (heat) involved in a chemical change will be determined. When alcohol burns it produces carbon dioxide and water as products. Energy is also released in the reaction. The alcohols that will be used are, methanol CH3OH, ethanol CH3CH2OH, propanol CH3(CH)2OH, butanol C4H9OH, octanol C8H18O, and paraffin wax C25H52. The heat obtained when a known mass of alcohol or paraffin wax burns will be used to warm a measured volume of water.
Alka Seltzer Lab  Jozelle Dela Torre May 29th, 2014 Introduction: A chemical reaction shows what ingredients (REACTANTS) are needed to make something new (PRODUCTS) Reactant (a) + Reactant (b) ----(makes)----à product (ab) Example: hydrogen (H) + oxygen (O) ----(makes)----à water (H2O) (a) (b) (ab) In order for a chemical reaction to occur, the particles (ATOMS) have to physically come in contact with one another. Anything that increases the chance (frequency - amount of times) of these atoms touching one another, will increase the rate (SPEED) at which the products (result) are formed. Purpose/Problem: To determine if the rate of the reaction (SPEED) can be increased by increasing the temperature of the reactants (ingredients). Hypothesis: If the water is at boiling point, then the reaction will occur faster. Materials: 3 beakers Thermometer 3 Alka-Seltzer tablets Stopwatch Mortar and pestle Source of hot water Ice cubes Graph paper Procedures: Hot water- Run water from the hot tap until it is hot as possible Fill beaker with 80 mL of hot water Use thermometer to take temperature of water.
Explain what it means to denature an enzyme. -To denature an enzyme means to change its shape by breaking the hydrogen bonds that holds its shape, thus rendering it useless. An enzyme can be denatured with heat, or with a change in pH. 5. What factors did you need to control in your tests?
The reaction that occurred with this step was displacement and metathesis in the form of gas formation. The balanced equation of this step looks as follows: CuSO4aq+Zns→Cus+ZnSO4(aq) Once this step was finished, the remaining copper was retrieved. First, to recover the copper HCl was added to remove all the zinc. When this happened, a yellow tint was observed in the liquid, as well as bubbling as the zinc was broken down. Once the copper dried out, it was weighed and came to a total of 240 mg.
The salts will be dissolved in distilled water by small quantities until the reaction reaches When ionic compounds dissolve in water, they either absorb energy from or release energy to the surroundings. If a chemical reaction absorbs heat from the surroundings, it is an endothermic reaction. If a solution releases heat to its surroundings, it is an exothermic reaction. The enthalpy of dissolution is the enthalpy change associated with the dissolution of a substance in a solvent at a constant pressure. The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies.
The bromine is acting first like an electrophile, and then after bromine has broken the π bond, a carbocation has formed, and a bromide ion has been created, the bromide ion then acts as the nucleophile and forms a bond with the carbocation. This experiment uses bromination, the specific name of halogenation with bromine. In order to for bromination to occur bromine must first be generated. This is done in situ through the oxidation of glacid acetic acid and puridinum bromide perbromide. Once generation is accomplished the available bromine can be brominated.
The salt crystal is made of positive and negative ions that hold the it together (eg. NaCl or Na+ and Cl-) by electrostatic ion-ion attractions (the attraction of opposite charges). When a salt dissolves in water, the electrostatic attractions between the ions are broken and each ion forms new electrostatic interactions with the water molecules (see figure 1). Whether this process creates an endothermic or exothermic reaction depends on the balance between the ion-ion forces of the solid salt that must be overcome and the dipole-ion forces that stabilize the dissolved ions in solution. Purpose In this experiment, you will be able to: o Distinguish between the terms: exothermic and endothermic reaction.
Name: 6.03: Calorimetry Data and Observations: Part I: Insert a complete data table, including appropriate significant figures and units, in the space below. Also include any observations that you made over the course of part I. (4 points) I observed that when the metal is placed inside the calorimeter, it transfers heat to the water making the water increase temperature while the metal will decrease temperature. I also noticed that the system was the metal and the surroundings is the water, this is because the water is taking in the heat from the metal making the water warm. Metal Name Mass of Metal Volume of water Initial temp.
The experimenter used 3 identical plastic cups and filled one with room temperature tap water, one with warm tap water and one with boiling tap water. Each cup was placed into the freezer and was checked every 15 minutes for signs of freezing. The experimenter found that the room temperature water showed the first signs of freezing and in the final outcome froze solid before the water in the other cups. His findings showed that water containing impurities, such as tap water, will freeze faster based on a lower starting temperature. The second case study was covered in an article by Science News.
By using this method of distillation a mixture is heated to a temperature at which several fractions of the compound is evaporated the distillate is then condensed and collected. Generally the component parts have boiling points that differ by as little as 20-30°C under a pressure of one atmosphere. However, cyclohexene and cyclohexanol have boiling points of 83°C and 161°C, respectively, and fractional distillation was used to separate the starting material from the desired product. The mixture is heated and boiled and the vapors produced are condensed and the distillate is collected and then tested by GC analysis. The Agilent 7890A Gas Chromatography System separates chemicals based on the ease with which they evaporate into a gas, also known as the volatility.