From the experimental data and through its analysis‚ the enthalpy of combustion for the five alcohols were determined; methanol‚ ethanol‚ propanol‚ butanol‚ and pentanol. As the line of best fit in the graph suggests‚ the enthalpy of combustion increased as the sizes of the molecules increased. This was predicted in the hypothesis and proves it to be correct. As seen on the graph‚ the enthalpy of combustion increases from 140kJ/mol for methanol‚ which has the smallest molecular mass‚ to 530kJ/mol
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these metals will be most reactive with hydrochloric acid‚and plan an investigation to test it out.The Metals given:Calcium‚Aluminium‚Iron‚Magnesium and Zinc. Prediction-I predict that the metal will be the most reactive with hydrocholoric acid is calcium because calcium is in Group 2 which is the alkaline earth metals in the periodic table and because calcium is at the extreme left side of the periodic table and as you go across a period‚the element change from reactive metals on the left to non
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effect of changing the concentration on the rate of reaction Aim: To investigate into the effect of changing the concentration on the rate of reaction Variables: · Keep the same volume · Keep the same length of magnesium · Change the amount of acid · Change the amount of water Method: · Set up apparatus as shown · Add 30ml of hydrochloric acid into the beaker · Measure 5cm of magnesium · Add the 5cm of magnesium to the hydrochloric acid · Put a bong onto the conical flask · Start
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this lab). This help us view the study of Law of Conservation of Mass‚ when either side of equation is equally balanced. The calculation for formula mass helps determine if you need to convert grams to a particular substance to moles‚ from a product. Moles are numbers that are in front of formulae. E.g.‚ 6NaCl‚ 6 is the equation for this formula. A mole would help you balance a skeleton equation‚ and also allows you to calculate how many moles are needed to take part in a chemical reaction. In the
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and the sodium hydroxide. When using glassware in experiments‚ it must be flushed out to make sure that cross contamination does not happen and that the only thing that would then be coating the beaker is the distilled water. When all of the glassware has been cleaned‚ some sodium hydroxide should be placed in a plastic weighing boat next to the scales and place the second weighing boat on the scales and weigh it then click the on tare button to set it back to zero and weigh out 1g of sodium hydroxide
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Chemical reactions are a part of everyday lives. Whether it is the burning of propane at a kitchen stove‚ or washing detergent reacting with dirt stains‚ chemical reactions are useful tools that have widespread applications. With so many reactions assisting our everyday activities‚ it is important that ways to optimise reaction rates are investigated. “Reaction rate‚ the speed at which a chemical reaction proceeds… may be defined in terms of the amounts of the reactants consumed or products formed
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Introduction The reaction between zinc and copper (II) sulphate is endothermic. If an excess of zinc powder is added to a measured amount of aqueous copper (II) sulphate in a calorimeter and the temperature change is recorded over a period of time‚ the enthalpy change of the reaction can be experimentally determined. Assumption 1. Mass of H2O in 100cm3 of CuSO4 solution is 100g 2. Specific heat of solution is 4.18 kJ kg-1 K-1 which is the same as the specific heat of water 3. Heat evolved
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aim and hypothesis Chemical reactions are accompanied by the release or absorption of energy. Reactions which release energy are described as exothermic and those which absorb energy are endothermic. The energy released in chemical reactions was previously stored as chemical potential energy in the reactants; this stored energy is called enthalpy. The aim of this practical is to observe and classify chemical processes as endothermic or exothermic‚ based on the changes in temperature measured and
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Enthalpy‚ represented by the sign ∆H in kJ/mol‚ is the heat change in a reaction. It shows whether how much heat is released or absorbed during the reaction. If the reaction is endothermic‚ the enthalpy would be positive and if the reaction is exothermic‚ the enthalpy would be negative. During a chemical reaction‚ which consists of breaking and creating bonds‚ heat is either absorbed or released. In this lab‚ the reaction uses the disassociation of an ionic compound ammonium nitrate shown in the
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2011 Chemistry I‚ Pd 11‚ Station K Evidence of Chemical Change Purpose To observe several chemical changes (reactions) and the evidence they exhibit for chemical change. Data See page 3 Analysis The two terms that describe possible energy change in a chemical reaction are Exothermic‚ for example when a gas is formed when Copper II Chloride and Aluminum are mixed‚ and Endothermic‚ for example when copper II Hydroxide is heated. There are many substances used in this experiment
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