creates an isolated system as it acts as a heat insulator between the cup and the surrounding. When a reaction happens bonds are created and destroyed causing energy to be released or absorbed. In a constant pressure‚ like in the coffee cup calorimeter‚ the change in energy equals to the enthalpy change of the reaction. Because enthalpy change of the reaction equals to the specific heat times the mass times the change in temperature‚ the amount of heat released or absorbed can be determined by measuring
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energy. Planning We will be using 6 different fuels to heat up 100ml of water‚ and find out the changes of the temperature. We will measure the temperatures of the water before and after the experiment. We will burn heat the water for exactly 2 minutes‚ and check the changes in temperature. The change in temperature will allow us to work out the energy given off the fuel by using this formula: Mass of water x 4.2 (water’s specific heat capacity) x temperature change = energy transferred from
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Tmaximum - Tminimum = 45 – 20 = 25 0C * Calculate the number moles of copper sulphate reacted: number of moles = concentration x volume = 0.5 x 0.025 = 0.0125 mol * Calculate energy released during the reaction (Q): Q = mass of CuSO4 x specific heat capacity x ΔT = 25 x 4.2 x 25 = 2625 J * Calculate ΔH for the reaction (energy change is negative because the reaction was exothermic): ΔH = -Q / number of moles = 2625 / 0.0125 = 210 kJmol-1 ‘Absolute Uncertainty’ = abs/unc ‘Percentage
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with on how to determine the caloric content of food by creating our own calorimeter. Measuring the energy content of three different food samples by using the change in water temperatures from the heat given off while burning the sample. To verify our results much further — equations‚ such as energy and heat capacity calculations‚ helped us establish on such results. As a result of the experiment‚ I learned and understand better the importance of choosing food with the right caloric content to get us
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Numerical Analysis of Auto-ignition of Ethanol Vaibhav Kumar Sahu1‚ Shrikrishna Deshpande1‚ Vasudevan Raghavan1‚* 1Department of Mechanical Engineering Indian Institute of Technology Madras‚ Chennai 600036‚ INDIA. Received 28 June 2011; accepted 5 August 2011‚ available online 24 August 2011 1. Introduction Ethanol is the most effective bio-fuel. Its easier production from agricultural feed-stocks‚ sugar cane and Fischer-Tropsch method makes it dominant among other bio-derived
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significant figures! ] SHOW YOUR WORK to get full credit. 1) Number of moles: 2) Pressure of each gas: 2. [ out of 16 pts ] When 11.1 g of lead reacts with 3.81 L of oxygen gas‚ measured at 1.00 atm and 25.0°C‚ 11.8 kJ of heat is released at constant pressure. What is ∆H° for this reaction? (R = 0.0821 L • atm/(K • mol)) 2Pb(s) + O2(g) → 2PbO(s) [ do not neglect significant figures! ] SHOW YOUR WORK to get full credit. 1) Determine
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Wrap the wire around a pencil for a slinky effect. Tighten the screws to assure that the wires are fastened. To determine the power P of the immersion heater‚ fill up half of a plastic cup with regular tap water (must be able to cover the wire)‚ and heat it with your immersion heater. By measuring the temperature of water as a function of time‚ and draw a graph‚ you can calculate the power P. The heater is lowered into the water and is connected to an AC power supply (alternating current). At the same
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URANIUM TALENT SEARCH EXAMINATION(UTSE) - 2011 (CBSE/ICSE) Time: 60 minutes(11 am - 12 noon) Class- IX F.M - 180(+3/-1 system) Declaration of Result in the internet(www.theuranium.org) : 15.03.2011 (There are 60 MCQs and each has one correct answer. You are required to darken the appropriate circle in the OMR answer sheet with the help of a HB pencil. Eraser can be used to change any answer. Note that improper darkening will make your answer sheet invalid by the computer. 3 marks will be given
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water vapor D.energy E.none of the above Answer Key: D Feedback: the characteristics of matter are discussed in chapter 3 Question 7 of 22 2.0/ 2.0 Points `If I apply 0.0385 kJ of heat to 0.0175 kg of an unkown metal‚ and I am able to raise its temperature from 27.0 °C to 30.0 °C‚ what is its specific heat? (Pay attention to units in this problem) A.0.73 J/g∙°C B.4.18 J/g∙°C C.0.15 J/g∙°C D.1.4 J/g∙°C E.none of the
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Enthalpy change‚ ΔH‚ is defined as the heat output of a system as it goes through a reaction under constant pressure. It is an important aspect of thermochemistry‚ which is the study of energy changes during a chemical or physical reaction . When we calculate enthalpy change‚ we always assume that the pressure is constant. We are able to calculate enthalpy change numerous ways‚ notably by the increase in heat‚ Q‚ given by an exothermic reaction or the heat absorbed by an endothermic reaction. To
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