Once Upon a Time by Gabriel OkaraOnce upon a time‚ son‚they used to laugh with their heartsand laugh with their eyes:but now they only laugh with their teeth‚while their ice-block-cold eyessearch behind my shadow.There was a time indeedthey used to shake hands with their hearts:but that’s gone‚ son.Now they shake hands without heartswhile their left hands searchmy empty pockets.‘Feel at home!’ ‘Come again’:they say‚ and when I comeagain and feelat home‚ once‚ twice‚there will be no thrice-for then
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[pic] Use words from the list to label the diagram. electron group nucleus symbol (2) b Hydrogen can be used as a clean fuel for cars. i When hydrogen burns in air‚ it reacts with another element. Complete the word equation for this reaction. hydrogen + ................... → water (1) ii Suggest one reason why hydrogen is called a clean fuel. (1)
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of Marble chips and Hydrochloric acid Aim: We will measure the loss in mass of the marble chips (CaCO 3 ) as it reacts with Hydrochloric acid (HCl). This one method of measuring the rate of reaction. We will use a balance to measure this mass loss as the reactants are used up to form product. Safety: * As Hydrochloric acid is corrosive wear a lab coat‚ gloves and safety goggles. * Take care when using the glassware not to cut yourself. * When the reaction is taking place Carbon
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Decomposition of Calcium Carbonate _INTRODUCTION_ RESEARCH QUESTION: What is the enthalpy change of the decomposition of calcium carbonate? BACKGROUND: Enthalpy in chemistry can be thought of as the energy contained within the bonds‚ or the internal energy‚ but it is not heat and you can only measure changes in it. When bond bonds break in the reactants energy is given off‚ when bonds form‚ energy is absorbed. If the energy absorbed is less than the energy released‚ then the reaction is exothermic
Free Thermodynamics Energy Calcium carbonate
Reaction Rate Coursework Aim To see how the concentration of a reactant affects the rate of reaction‚ in this case sodium thiosulphate and acid. Scientific Background For a reaction to occur‚ the particles of the reactants must be colliding with each other with enough energy‚ the amount of energy needed for the reaction is called activation energy. Activation energy is altered by temperature‚ concentration‚ surface area of and the pressure on the reactants. Stirring the reactants also increases
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Aim: determine the mass of calcium carbonate in chicken eggshells and hence its percentage by mass Apparatus Uncertainty 25.00 cm3 pipette ± 0.03 cm3 50.00 cm3 burette ± 0.05 cm3 250.0 cm3 volumetric flask ± 0.3 cm3 50.0 cm3 measuring cylinder ± 0.5 cm3 Electronic balance ± 0.01 g Uncertainty of apparatus Measurement Mass of eggshell = 3.15 ± 0.01 g Volume of HCl added = 50.00 ± 0.5 〖cm〗^3 Volume of solution = 250.0 ± 0.3 〖cm〗^3 Volume of NaOH pipetted = 25.00 ± 0.03 〖cm〗^3
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react with hydrochloric acid; and 1 cm3 of element X has a mass of 1.8 grams. Is element X a metal or non-metal? Give the reasons for your answer. Element X is most likely a typical non-metal. First of all‚ element X melts in boiling water; non-metals typically have low melting and boiling points. Furthermore‚ element X is unable to react with hydrochloric acid. This greatly indicates that element X is a non-metal as most non-metals fail to react with hydrochloric or dilute acids. In order
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The effect of temperature on a reaction rate In this experiment I shall be investigating how temperature affects the rate of reaction Rates of reaction The Factors that affect the rate of reaction are temperature‚ surface area‚ concentration‚ catalysts‚ light and pressure Surface area – Surface area is the amount of solid surface that is available for reaction - Only affects solids so this will not affect our
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found that‚ in acidic pH environment‚ the reaction rate of starch being broken down by alpha amylase is less than that of the reaction rate at a neutral and slightly basic pH environment. This finding partially supports our hypothesis. The spectrophotometer readings in our experiment measured the absorbance of 3-amino-5-nitrosalicylic acid‚ a colored molecule formed after dinitrosalicylic acid (DNSA) has reacted with the products of the enzymatic reaction or the simple sugars. Therefore‚ the absorbance
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Effect of Concentration on Reaction Rate Aim: To use a simple reaction between sodium thiosulphate and hydrochloric acid to discover concentration this determines how fast chemical reactions occur. Independent Variable: Concentration of hydrochloric acid (%) Dependent Variable: Time taken for chemical reaction to take place (sec) Hypothesis: My prediction is that the increased concentration of the thiosulfate will in turn lead to an increase in the rate of reaction. This is a well informed
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