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Determination of the enthalpy change associated with a reaction
Lab report for chemical kinetics: factors influencing the rate of a chemical reaction
Discussion on enthalpy change
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Chemistry Aim- To determine the enthalpy change for the reaction of between cooper sulphate and zinc. Materials Required- Calorimeter Glass Thermometer Weighing Machine Digital Stop Watch Measuring Cylinder Cuso4 . 5H2o Zinc Metal Powder Distilled Water By adding the access amount of zinc in the constant amount of aqueous cooper sulphate and measuring the change in temperature over time, the chande in enthalpy of the reaction can be determined using calorimeter calculation. Materials Required- Procedure- Establish a data table that records the temperature[Celsius] and time[ seconds]. place 25.0ml of cooper sulphate from the berette into the polystyrene cup. Weigh 6g of zinc powder on a small piece of paper, although there is Determine the enthalpy change in enthalpy change, when there are 6g of zinc powder ΔH= M×c× △T Cooper sulphate = 25cm3 Specific heat capacity = 4.18J g-1 Temperature change = 25-60=-35 Enthalpy change [Joules] = -[25×4.18×35] = -3,657.5 Molar enthalpy change = Enthalpy change / Solution Moles = (-3,657.5)⁄0.0025 = -1,427,000= -1427 KJ Mol-1 Determine the enthalpy change in enthalpy change, when there are 7g of zinc powder ΔH= M×c× △T Cooper sulphate = 25cm3 Specific heat capacity = 4.18J g-1 Temperature change = -25.5-61= -35.5 Enthalpy change [Joules] = -[25×4.18×35.5] = -3079.75 Molar enthalpy change = Enthalpy change / Solution an exothermic reaction is when the heat is given out by the system and △H is negative. The change in temperature upon adding Zinc in a perfect situation, where no heat is lost. The gradient shows that temperature decreases when Zinc was added in it. Very steep gradient line shows the speed of the reaction at which temperature was decreasing. There can be percentage errors and uncertainties or heat loss in surrounding while executing the experiment. Conclusion- The concept of displacement reaction of Zinc in cooper sulphate is exothermic, as heat is released out while reacting. A powder substance Zinc reacts faster, when it is added to cooper sulphate solution as the total surface is high. After reaching of the peak, the temperature started falling down, as the solution starts cooling down and Heat is lost in the surrounding. An ideal situation shows the change in temperature, which we can use it in calculations; It is possible that the concentration of copper sulphate was lower and therefore less zinc reacted, releasing less energy than expected. We took four different samples of zinc in order to check the difference in enthalpy. Zinc replaces cooper in cooper sulphate, because it is more reactive and it also has very low solubility. So, this is how with the help of redox reaction we determined the enthalpy change
== = Hess’s law of heat summation states that the value of DH for a reaction is the same whether it occurs directly or as a series of steps. This principle was used to determine the change in enthalpy for a highly exothermic reaction, the combustion of magnesium metal. Enthalpy changes for the reactions of Mg in HCl (aq) and MgO (s) in HCl (aq) were determined experimentally, then added to that for the combustion of hydrogen gas to arrive at a value of –587 kJ/mol Mg.
Introduction: The purpose of this lab was to cycle solid copper through a series of chemical forms and return it to its original form. A specific quantity of copper undergoes many types of reactions and goes through its whole cycle, then returns to its solid copper to be weighted. We observed 5 chemical reactions involving copper which are: Redox reaction (which includes all chemical reactions in which atoms have their oxidation state changed), double displacement reaction, precipitation reaction, decomposition reaction, and single displacement reaction. 4HNO3(aq) + Cu(s) --> Cu (NO3)2(aq) + 2H2O (l) + 2NO2(g) Oxidation reduction reaction Cu (NO3)2(aq) + 2 NaOH (aq) --> Cu (OH)2(s) + 2 NaNO3(aq) Precipitation Reaction Cu (OH)2(s) + heat --> CuO (s) + H2O (l) Decomposition reaction CuO (s) + H2SO Data Results: (mass of copper recovered / initial mass of copper) x 100 Mass of copper recovered: 0.21 Initial mass of copper: 0.52 (0.21/0.52)x100 =40.38%.
According to recent statistics, zinc is the third most commonly used nonferrous metal in the United States. This unassuming metal was among the first minerals exploited by Man, used as a decorative material for thousands of years, although it never achieved the fame and notoriety of other metals such as gold or silver. In more recent times, new extraction and processing methods have allowed Man to produce higher-quality zinc than ever before, and to use it in an astonishingly high number of chemical and high-tech applications.
8. Continue stirring. Record the temperature at which crystals begin to appear in the solution.
This was found by dividing the heat transferred by the mass times the temperature change (Cp=Q/m x ΔT) of all three trials. Then the specific heats of all the trials and divided that by the number of trials (three). All of the specific heats add up to 1.07 and 1.07 divided by three equals 0.36, the average. The average percent error of the experiments is 7.7% because all of the percent errors from the trials added together equals 23 and 23 divided by three equals
During an intense game, athletes need a way to soothe their acute injuries leading them to the instant cold packs in their team’s med kit as fans huddle under blankets clutching hot packs between frigid fingers. What these two groups don’t realize is that they are utilizing chemical reactions in order to either expel or absorb heat. Chemical reactions that were discovered and utilized by inventors to create the very packs they are using. The chemicals inside each respective pack have various properties and applications that make them useful in their thermochemistry reactions. The compounds used are salts including sodium acetate and calcium chloride for hot packs and ammonium nitrate for cold packs.
Specific heat capacity of aqueous solution (taken as water = 4.18 J.g-1.K-1). T = Temperature change (oK). We can thus determine the enthalpy changes of reaction 1 and reaction 2 using the mean (14) of the data obtained. Reaction 1: H = 50 x 4.18 x -2.12.
The objective of this experiment was to identify a metal based on its specific heat using calorimetry. The unknown metals specific heat was measured in two different settings, room temperature water and cold water. Using two different temperatures of water would prove that the specific heat remained constant. The heated metal was placed into the two different water temperatures during two separate trials, and then the measurements were recorded. Through the measurements taken and plugged into the equation, two specific heats were found. Taking the two specific heats and averaging them, it was then that
One possible source of experimental error could be not having a solid measurement of magnesium hydroxide nor citric acid. This is because we were told to measure out between 5.6g-5.8g for magnesium hydroxide and 14g-21g for citric acid. If accuracy measures how closely a measured value is to the accepted value and or true value, then accuracy may not have been an aspect that was achieved in this lab. Therefore, not having a solid precise measurement and accurate measurement was another source of experimental error.
be yes as I will then be able to use enthalpy change of reaction to
In a 250ml beaker place 100mls of water, measure the temperature of the water and record this initial temperature onto a table. Set the timer and add one teaspoon of Ammonium Nitrate to the water, stir this continuously until the Ammonium Nitrate has dissolved. After 1 minute measure the temperature and record it, do this for a further 2 minutes (3 minutes in total). Repeat this process for a total of 10 teaspoons.
The Electrolysis of Copper Sulphate Aim Analyse and evaluate the quantity of Copper (Cu) metal deposited during the electrolysis of Copper Sulphate solution (CuSo4) using Copper electrodes, when certain variables were changed. Results Voltage across Concentration of solution electrode 0.5M 1.0M 2.0M 2 5.0 10.6 19.5 4 10.5 19.8 40.3 6 14.3 26.0 60.2 8 15.2 40.4 80.3 10 15.0 40.2 99.6 12 15.1 40.0 117.0 Analysing/Conclusion The input variables in this experiment are; concentration of the solution and the voltage across the electrodes. The outcome is the amount of copper gained (measured in grams) at the electrodes. By analyzing the graph, we can see the rapid increase of weight gained for the 2.0 molar concentration as the gradient is steeper.
The process of refining zinc has two main steps: roasting and electrolysis. Both of these processes use a lot of energy. The roasting stage involves heating the furnace chamber up to temperatures between 700 oC and 1000oC Roasting is a way of oxidizing zinc sulphide and getting impure zinc oxide also known as "Z...
To investigate the temperature change in a displacement reaction between Copper Sulphate Solution and Zinc Powder
Based on your experiments what is the formula of the colorless gas that is released when heating the malachite?