Enthalpy of Neutralisation.
TITLE: Enthalpy of Neutralisation. AIM AND HYPOTHESIS: My aim in this experiment is to compare the enthalpy change of neutralisation by titration, for each reaction between the following 3 acids: Sodium hydroxide (NaOH) and hydrochloric acid (HCl) - pH 1 Sulphuric acid (H2SO4) and NaOH - pH 1 NaOH and Ethanoic acid (CH3COOH) - pH 2.88 - 3 I predict the reaction between the above-mentioned acids would be exothermic because heat will be given off during the reactions and the temperatures will be rising due to the heat evolved. I also predict the reaction between the chemicals is exothermic because the energy content of the products is less than that of the reactants, resulting to heat being given out from the system. These predictions show that the stronger the acid used in neutralization, the more energy is released per mole of water. I will be able to compare these predicted energy changes with my actual results after my experiment. When I have my results- the temperature change from beginning to end of the experiment - I can use the equation Energy change = mass of solution x temperature change x specific heat capacity of water to work out the actual energy change. In neutralization, we assume that the density of the acid/alkali is the same as that of water, so volume of acid = mass of acid. We know that the specific heat capacity of water is always 4.2 Jk - 1 g
To investigate the effect of temperature on the rate of reaction
GCSE Triple Science Chemistry: Rate of Reaction Aim: To investigate the effect of temperature on the rate of reaction Define: Chemical Reaction A chemical reaction is a process that results in the interconversion of chemical substances. The substance or substances initially involved in a chemical reaction are called reactants. Chemical reactions are characterised by a chemical change, and they yield one or more products which are, in general, different from the reactants. Classically, chemical reactions encompass changes that strictly involve the motion of electrons in the forming and breaking of chemical bonds, although the general concept of a chemical reaction, in particular the notion of a chemical equation, is applicable to transformations of elementary particles, as well as nuclear reactions. [Source: Wikipedia] Collision Theory - Energy of the Collision Activation Energy Regardless of whether the species are orientated correctly, a reaction will still not fail to occur unless the particles collide with a certain minimum energy called the activation energy of the reaction. Activation energy is the minimum energy required before a reaction can occur. This can be shown on an energy profile for the reaction. For a simple over-all exothermic reaction, the energy profile looks like this: If the particles collide with less energy than the activation energy, nothing
Investigate the effect of changing the concentration of sodium hydroxide (alkali) on the volume of hydrochloric acid needed to neutralize a fixed volume of alkali by measuring the temperature and noting colour changes of the solution mixture.
College: Brookhouse six form Student: Miss Vincia Phillip Teacher: Mrs Zainab Topic: Titration/ neutralisation reactions Title: Titration/ Neutralisation Aim: To investigate the effect of changing the concentration of sodium hydroxide (alkali) on the volume of hydrochloric acid needed to neutralize a fixed volume of alkali by measuring the temperature and noting colour changes of the solution mixture. Background knowledge: Neutralization occurs when an acid is made to react with a base. In this reaction, the chemical opposites cancel each other out. Alkalis contain OH? (aq) ions, whereas acids contain H? (aq) ions. In the neutralization reaction the OH? and H? ions come together to form water; (H O), which is a neutral substance. The reaction to be carried out will be between Sodium hydroxide (NaOh) and Hydrochloric acid (HCl). Equations: Sodium hydroxide +hydrochloric acid›Sodiumchloride+ Water NaOh (aq) +HCl (aq) ›NaCl (aq) +H O (aq) Equation: H? (aq) + OH? (aq) ›H O (l) In this reaction there are four different ions. These are Na, OH?, H and Cl?. The reactivity series shows elements in order of their reactivity. Reactivity is based on how vigorously elements react with oxygen, air and dilute acid. In displacement reactions, more reactive elements displace others from their compounds and take their place. Spectator ions are ions which are indirectly
chemistry coursework
Experiment to determine the factors which affect the rate of oxidation of acidified potassium iodide solution by hydrogen peroxide. Plan As described in my preliminary introduction I intend to carry out an investigation to determine the factors which affect the rate of oxidation of acidified potassium iodide solution by hydrogen peroxide. H202 + 2KI + H2SO4 = K2SO4 + 2H2O + I2 I intend to vary the amount of potassium iodide entered into the 100cm³ solution (potassium iodide included in the solution). Potassium iodide is the independent variable. I plan to keep the volume of the solution at 100cm³. The dependant variable is time as this will vary depending on how quickly the solution turns a purple/black colour and the black cross marked on the paper below is not visible. I intended to keep the amount of sulphuric acid constantly at 40 cm³ also keeping the amount of hydrogen peroxide at 15 cm³ and the amount of special indicator at 5 cm³. In some cases where potassium iodide, sulphuric acid, hydrogen peroxide and the special indicator do not equal 100 cm³. Water is added to the solution to equal 100 cm³. . Potassium iodide is the independent variable therefore its volume must be changed in every solution. The apparatus required for this experiment consists of a stop clock, a 100 cm³ beaker, a 100 cm³ measuring cylinder, a 50 cm³ measuring cylinder, a 10 cm³
Chemistry Investigation on neutralisation reaction.
Chemistry Investigation on neutralisation reaction Plan Neutralisation is the reaction that occurs when an acid has its acidity, that is its hydrogen ions removed by, another chemical containing OH- hydroxide ions. Chemicals that can cancel out an acid in this way are: bases (metal oxides or hydroxides), alkalis (bases that dissolve), metals (e.g. magnesium) or metal carbonates (e.g. marble chips) All of these have a similar way of removing the hydrogen from the acids (they swap it or their metal atoms) but the reactions are quite different. They will all get quite hot if the acid is strong enough, but only the last two will make bubbles. Metals form hydrogen gas, carbonates make carbon dioxide. All of them will leave a neutral chemical after the reaction has finished, if all the acid has been used up. Titration is a technique used to calculate the concentrations or amounts of substances. In an acid base titration you may have an acid that you don't know the concentration of, and a base whose concentration you do know. The technique is to measure out accurately a volume of the alkali of unknown concentration into a flask, and fill up a burette with the acid. Add some indicator solution to the acid in the flask, so that when all the acid has reacted with the base, there will be a colour change. The burette is graduated. You then open the tap on the burette and let the acid
To see how the concentration of acid, reacting with potassium carbonate, affects the rate of reaction
Aim: To see how the concentration of acid, reacting with potassium carbonate, affects the rate of reaction. Intro: This is the reaction I am using in my coursework: 2HCl + K2CO3 CO2 + 2KCL + H2O In order for substances to react together the particles in the substances must collide with each other and the collision must have enough energy. If there isn't enough energy, no reaction occurs. If there are lots of successful collisions then a lot of CO2 will be produced. The rate of a reaction depends on how many successful collisions there are in a given unit of time. A reaction can be made to go slower or faster by changing the concentration of a reactant. Acid particle Water molecule Potassium carbonate tablet 1 2 In dilute acid, there are not so many acid particles (see diagram 1). This means there is not much chance of acid particles hitting a potassium carbonate particle. In a more concentrated solution of acid, there are more acid particles (see diagram 2). There is now more chance of a successful collision occurring. Concentration is how much of a substance there is in a certain volume and is measured in Moles per litre of solution (M). The concentration of a solution is the amount of solute, in grams or Moles that is dissolved in a litre of solution. That is what my coursework is mainly about. I predict that on my
An investigation into the factors affecting the temperature rise of water heated electrically.
An Investigation Into the Factors Affecting The Temperature Rise of Water Heated Electrically Planning Aim: The aim of this investigation is to determine the factors affecting the temperature rise of water which is being heated electrically. Variables: The variables in this experiment are: ) Time 2) The Power Of The Heater 3) The Mass Of Water 4) The Temperature Rise The Possible Experiments There are several experiments which can be carried out to investigate the factors affecting water being heated electrically. ) Varying the mass of water used and the temperature rise and keeping the power of the heater and the time fixed. In this experiment the mass of water would be varied and keeping the power of the heater the same, the temperature rise could be record to produce an array of results. 2) Varying the power of the heater and the temperature rise, and keeping the mass of water and the time taken fixed. In this experiment the power of the heater would be varied and he again the temperature rise would be record to take results. 3) Finally the time could be varied with the temperature rise being varied, keeping the power and mass constant. In this experiment the time the heater was left on would be varied and the temperature rise would be recorded. From these 3 I have decided to choose 1) because number 3 is trivial, it is too simple and will not tell me
Investigation into the effect of acid/alkali strength on the heat change when acids and alkalis are mixed
Investigation into the effect of acid/alkali strength on the heat change when acids and alkalis are mixed Planning The main aim of this experiment is to investigate the heat change when acids and alkalis are mixed. The temperature of the acid and alkali that are going to be mixed will be taken prior to mixing, and after they have been mixed in a polystyrene cup. The maximum temperature rise will be noted as this will be the biggest heat change that has occurred. The highest temperature after mixing and the temperature prior to mixing will be subtracted to give the heat change. To ensure that this is a valid test the volume of the acid and alkali will be kept constant at 40cm3. The volume will be kept constant because if there were a differing volume of acid to alkali this would have an influence on the temperature rise as there is not the same amount of solution. The only variable in this experiment will be the strength of the acid and alkali. This will allow us to examine the manner in which the heat evolved differs for differing strengths. Comparisons can then be undertaken to see how concentration affects the heat change in set volumes of acid and alkalis. When the acid and alkali of the same volume are mixed, this will cause the process of neutralisation to occur. Neutralisation is the reaction between an acid and a base. It is the formation of a bond between
The Effect of pH on the Strength of Keratin (hair protein).
Science Plan The Effect of pH on the Strength of Keratin (hair protein) Relevant Information: Keratin is a fibrous protein and has a structural function. Fibrous proteins contain polypeptides that bind together to form very long fibres running parallel to each other. These fibres are linked by cross-bridges that make the protein strong and insoluble. The main constituent of hair is the protein keratin. Keratin can also be found in horns, nails, claws and feathers. These examples suggest keratin has a strong structure. Like most other proteins it is made of monomers called amino acids. All Amino acids contain both an acidic carboxylic group (-COOH) and a basic amino group (-NH2); there is also an R group that changes with each different amino acid. They all consist of carbon, hydrogen, oxygen and nitrogen atoms. Keratin also contains a high concentration of the amino acid cysteine; this contains a sulphur atom. The sulphur atoms from two cysteines join together, forming a very strong disulphide bond. These bonds are covalent and form strong links making the tertiary structure of the protein very stable. The disulphide bonds occur down the length of the keratin fibre and the cross-linking between the keratin chains account for the strength of hair. Within each hair strand the keratin chains are also linked with ionic, salt and hydrogen bonding. Hydrogen bonding occurs from
The Effect of Concentration on the Rate of Reaction when you React Hydrochloric Acid with Marble Chips
Introduction To observe how concentration affects the rate of reaction I will be doing an experiment involving an acid, hydrochloric acid (HCl) and marble chips, Calcium Carbonate (CaCO3). This experiment requires the following apparatus: * Conical flask * Thistle tube * Rubber stop cork * Delivery tube * Burette * Plastic container In this experiment some factors must be varied and others controlled. The concentration of the acid needs to vary. This is because the experiment involves measuring the affect of concentration on the rate of reaction. The volume of the acid used in the experiment needs to be the same because this will make it a fair test. Preliminary work has shown that 25cm3 of acid is a good amount to use. The mass of marble chips (calcium carbonate) needs to be kept constant. Preliminary work has also shown that an appropriate mass of chips to be used is 1.5 grams. The size of the marble chips must be kept relatively the same because the surface area affects the rate of reaction. It affects the rate of reaction because finer particles cause the surface area to increase as they take up more space than larger chips and therefore the extra surface area leads to a quicker reaction because there are more collisions. Collision theory states that the rate of reaction increases depending on how often and how hard the particles collide with each other in order
