The effects of concentration on reaction rates
John Saunders (11R) The effects of concentration on the rate of reaction between magnesium (Mg) and Hydrochloric acid (HCl). Introduction: In this experiment, I am going to find out what happens when different concentrations of hydrochloric acid are mixed with the same amounts of magnesium. The probable outcome of this is that the reaction will be more vigorous to start with, meaning the reaction would end up being completed faster, if the concentration was to be higher than normal. This would happen because there would be more atoms of hydrogen and chlorine in a higher concentrated solution, to react with the magnesium. As you can see, the circles that represent the hydrogen and chlorine atoms of the hydrochloric acid find it a lot harder to fit inside the right-hand rectangle, that is the same area as the left rectangle (the rectangles representing the solution of acid). This means that the right-hand rectangle is more concentrated, as the hydrogen and chlorine atoms take up more space. If a piece of magnesium were to be placed in the rectangles, then the more vigorous (and faster) reaction would take place in the right-hand rectangle. This is because the magnesium would be confined to the (smaller) area where there aren't hydrogen or chlorine atoms, so the collision rate is likely to be higher. Prediction: I predict that the higher the concentration of HCl, the
A discussion of Atoms.
Atoms There are 112 elements although elements 110-112 are as yet unnamed. These 112 elements are organized in the periodic table: The modern chemical symbols were introduced by Berzelius. Rows of elements are called "periods" and columns of elements are called "groups" (1A, 2A 3B etc.). There are three general classes of elements distinguished by their physical properties: the metals (generally shiny and conduct electricity), the non metals (not shiny, sometimes gasses at STP and poor conductors of electricity) and the metalloids (properties in between those of metals and non metals.). Some groups have special names: Group 1A: Alkali metals Group 2A: Alkali earth metals Groups 3B-2B: Transition metals Group 7A: Halogens Group 8A: Noble gases Many of the heavier elements are unstable - which means that the atoms of those elements break apart very quickly. Elements within a group share similar chemical properties. Other chemical and physical properties of the elements can be deduced from their position in the periodic table. The structure of the periodic table and thus their chemical and physical properties is directly related to their atomic structure. Atomic Weights Most elements can be found on earth (with the exception of those elements that too unstable and thus must be synthesized in the laboratory). Since all elements have isotopes then we must consider how
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
Analysis of Neutralisation of NaOH
Analysis The results of my investigation show that the larger the amount of hydrogen in the acid, the smaller the amount of acid needed to neutralise the alkali. This is because when an acid is added to an alkali each hydrogen ion in the acid joins an hydroxide ion in the alkali to form neutral water. Hydrogen ion from Hydroxide ion from Neutral water acid alkali The solution only becomes neutral if the amount of hydrogen ions and the amount of hydroxide ions are equal. If there were more hydrogen ions than hydroxide ions then once every hydroxide ion joined with 1 hydrogen ion there would be hydrogen ions left meaning the solution would become acidic. If there were more hydroxide ions than hydrogen ions then once every hydrogen ion joined with 1 hydroxide ion there would be hydroxide ions left meaning the solution would become alkaline. When an acid contains more hydrogen then there are a greater number of hydrogen ions per ml than in an acid containing less hydrogen so it will be stronger. For example in sulphuric acid (H2SO4) there would be more hydrogen ions than in the same amount of hydrochloric acid (HCl), twice as many because there are twice as many in the formula. The alkali in my experiment remained the same throughout (NaOH)
Suitability Test
Suitability Test Introduction My work is about a scenario where a building contractor that wishes to develop an area of land into new houses for families. The Environment Agency has been asked to check the land for contamination. My task is to decide which method of testing Ph values in soil is most suitable for an environmental scientist. The desirable characteristics should be: * Safe: So no one is harmed whilst using it. * Easy To Use: So its easier to carry out more than once * Accurate: So that the readings are reliable. * Light: So it is easy to carry around. * Portable: So that it is easy to transport around. * Durable: So it can last longer. * Small: So that it's easier to transport. * Cheap: So it saves money and is cost effective. * Energy Efficient: So it doesn't need a mains power supply. Evaluation RED= Poor ORANGE= Average GREEN= Good Cost Litmus U.I. Solution Soil Probe pH Probe About 3p £4.15 £6.95 £294.46 Accuracy Litmus U.I. Solution Soil Probe pH Probe Acid/Alkali 0.5 .0 0.01 Time for results Litmus U.I. Solution Soil Probe pH Probe 5 Minutes 5 Minutes Minute 5-10 Minutes Sensitivity Litmus U.I. Solution Soil Probe pH Probe Acid/Alkali -14 Full Range 4-7 Full Range - More Accurate Durability Litmus U.I. Solution Soil Probe pH Probe ***** *** **** **** Easy To Use Litmus U.I. Solution
How the Concentration of Acid in a Solution affects the Rate of Reaction
Investigation into: How the Concentration of Hydrochloric Acid in a Solution affects the Rate of Reaction Aim: This experiment was to observe how the concentration affects the rate of reaction between chemicals. The two chemicals used in our experiment were Sodium Thiosulphate and Hydrochloric Acid. Introduction: The rate of reaction is basically the speed of how fast the reaction occurs between two reactants. You measure this speed in seconds, and have to set an achieving limit, which is a standard point of the reaction where a change is noticed and that is where the time must be recorded. A reaction is the simply the collision of the particles in two different substances (reactants). This essay is about writing how we observed the chemical reaction we carried out. Now here's the bit where the story gets interesting... My Prediction: My prediction is that: as long as the chemicals react in the same amount as was set, the speed of the reaction will be faster as the concentration (molarity) of the Hydrochloric Acid is increased. I predicted this because generally, when something has a higher concentration, it reacts quicker than when it has a lower concentration. This theory is ~ "Increasing the concentration increases the rate of reaction". This is because when there are more particles present, there is more collision between the particles; this increases the rate of
Covalent bonding
Covalent bonding is an intermolecular form of chemical bonding characterized by the sharing of one or more pairs of electrons between two components, producing a mutual attraction that holds the resultant molecule together. Atoms tend to share electrons in such a way that their outer electron shells are filled - this is referred to as electron configuration. Such bonds are always stronger than the intermolecular hydrogen bond and similar in strength to or stronger than the ionic bond. In contrast to the ionic and metallic bond, the covalent bond is directional, i.e. the bond angles have a great impact on the strength of the bond. Because of the directional character of the bond, covalently bound materials are more difficult to deform than metals. The cause of the directionality is the form of the s, p, d, and f orbitals. In organic chemistry, the directionality of the bonding is often described by hybrid orbitals. Covalent bonding most frequently occurs between atoms with similar electronegativities. For this reason, non-metals tend to engage in covalent bonding more readily since metals have access to metallic bonding, where the easily-removed electrons are more free to roam about. For non-metals, liberating an electron is more difficult, so sharing is the only option when confronted with another species of similar electronegativity. However, covalent bonding involving
Rates of reaction of agar with different HCL concentrations
Rates of Reaction Background Info Collision Theory Different reactions can happen at different rates. The rate of the reaction tells us how quickly a chemical reaction happens. Reactions that occur slowly have a low rate of reaction. Reactions that happen quickly have a high rate of reaction. For example, rusting is a slow reaction: it has a low rate of reaction. Burning and explosions are very fast reactions: they have a high rate of reaction. For a chemical reaction to occur, the reactant particles must collide. But collisions with too little energy do not produce a reaction. The particles must have enough energy to overcome the activation energy in order for the collision to be successful in producing a reaction. Activation energy is the energy needed to start a reaction. The rate of reaction depends on the rate of successful collisions between reactant particles. The more successful collisions there are, the faster the rate of reaction. There are two ways to find the rate of a reaction: * Measure the rate at which a reactant is used up * Measure the rate at which a product is formed The method chosen depends on the reaction being studied. Sometimes it is easier to measure the change in the amount of a reactant that has been used up; other times it is easier to measure the change in the amount of a product that has been produced. Reactions where a single species
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
Chemistry revision notes. Atomic Structure and Bonding, Electrolysis, Acids and Alkalis.
Atomic Structure and Bonding (F) Atoms, Molecules and Ions. AN ATOM is the smallest particle of an element. They cannot be split into smaller particles in chemical reactions. Iron is made of iron atoms (Fe). Sulphur is made of sulphur atoms (S) A MOLECULE is a small group of atoms joined together. The atoms may be the same (e.g. O2) or different (e.g. H2O). The chemical formula shows the number and type of atoms present. Non-metal compounds are made of molecules: Carbon dioxide contains CO2 molecules Methane (natural gas) contains CH4 molecules AN ION is an atom or group of atoms with an electrical charge (+ or -). Metal compounds such as sodium chloride or copper sulphate contain ions. Sodium chloride is made of Na+ and Cl- ions Magnesium Oxide is made of Mg2+ and O2- ions Note that metals form positive ions while non-metals form negative ions. A solid is represented by (s). e.g. H2O(s) is ice. A liquid is represented by (l) e.g. Fe(l) is molten iron. A gas is represented by (g) e.g. H2O(g) is steam. A solution in water is represented by (aq). Salt dissolved in water is NaCl(aq). You should remember that the common gases are diatomic (have 2 atoms in each molecule). These are Oxygen O2; Hydrogen H2; Nitrogen N2; and Chlorine Cl2. Elementary Particles Atoms are made up of smaller particles called protons, neutrons and electrons. The protons and neutrons
