To investigate the amount of silver nitrate deposited on the cathode and anode when dipped in silver nitrate solution and weighed at two-minute intervals.
Chemistry Coursework Preliminary Aim: Aim 1) To investigate the amount of silver nitrate deposited on the cathode and anode when dipped in silver nitrate solution and weighed at two-minute intervals. Aim 2) To investigate the amount of silver nitrate deposited on the cathode and the anode when put into silver nitrate solution at different current levels Prediction: Faraday's First Law of electrolysis states that: "The mass of any element deposited during electrolysis is directly proportional to the number of coulombs of electricity passed" Faraday's Second Law of electrolysis states that: "The mass of an element deposited by one Faraday of electricity is equal to the atomic mass in grams of the element divided by the number of electrons required to discharge one ion of the element." By looking at Faradays current we could tell that the time is directly proportional to the current, so any changes in the time would cause changes to the current. Apparatus > Battery Pack > Stop watch > Silver nitrate solution > Beaker > Crocodile clips > Weighing scale > Ampmeter > Stopwatch Method: (1st Experiment) * We prepared 50 cm3 of Silver nitrate Solution (Aq) in a beaker. * We then connected the power pack to the 2 metals, we had initially weighed them before connecting them using crocodile clips * We sipped the two
Background information on Electrolysis.
Background information on Electrolysis Electrolysis is a chemical process by which electrical currents can be passed through solutions. Pure water cannot conduct electricity, but if a salt such as Sodium Chloride is dissolved in it, the solutions will start conducting if two electrodes are placed in it with a battery that provides the initial current. When we close the switch, copper ions on the anode will start to move through the solution to the cathode. The copper atoms have already given up two electrons to become ions and their electrons are free to move in the wires. Closing the switch pushes electrons clockwise and forces some copper ions into the solution. The cell pushes the ions from the anode to the cathode. At the same time, it pushes the free electrons around the wires (these electrons are already spread through the wires). Electrons in the cathode recombine with copper ions from the solution, forming a new layer of copper atoms. Gradually, the anode is eroded and the cathode grows. Insoluble impurities in the anode fall to the bottom in a pile. This valuable bi product is removed. Gold, silver, platinum and tin are insoluble in this electrolyte and so do not deposit on the cathode. They form a 'sludge' that collects under the anodes. If the substance the metal rods are placed in is not in liquid form, the current with not conduct. To prove that
Causes of Global Warming
Global Warming Global warming is the term used to describe a gradual increase in the average temperature of the Earth’s atmosphere and its oceans, a change that is believed to be permanently changing the Earth’s climate. Even though it is an ongoing debate, it is proved by the scientists that the planet is warming. The 29th century is experiencing a continued increase of Earth’s mean atmospheric temperature by about 1.4 degrees F and about two thirds of it occurring since 1980. This is global warming is affecting the nature’s balance and has a huge impact on life like continued heat waves, and sudden occurrence of storms and floods. Don’t we see time to time the epidemics that are devastating to human life and the flooding of the farmlands that puts economy in a deep hole? Scientific evidence indicates that since 1950, the world’s climate has been warming, primarily as a result of emissions from non -stop burning of fossil fuels and the razing of tropical forests. Since the industrial revolution till this day, there is a constant emission of the carbon into the atmosphere, everything we do we leave carbon footprints. It is a man made cause of the global warming. The global emissions jumped 3 percent in 2011 and are expected to jump another 2.6 percent in 2012, researchers reported. The greenhouse effect is a process by which the greenhouse gases absorb
Design an experiment to choose optimum conditions for Electroplating
Design an experiment to choose optimum conditions for Electroplating Introduction: Electroplating involves the careful control of conditions and of electrolyte. Some of the factors that affect the quality and quantity of the deposit formed in an electroplating cell are observed in this practical. Aim: The aim of this practical is to design and perform an experiment to determine the best and most favourable conditions for electroplating. Diagrams: anode: Cu (s) ------ Cu 2+ (aq) + 2e- (oxidation) cathode: Cu 2+ (aq) +2e- ------ Cu (s) (reduction) Independent variable: concentration of the copper(II) sulfate solution. Dependent variable: volume of the electrolyte solution, time, distance between the electrodes and the current. Method: . Using the scourer, we cleaned the copper strips. Measured and recorded their mass. 2. We adjusted the current value using the variable resistor. Placed both copper electrodes into the cell, making sure they were not in contact. Filled the cell with the copper(II) sulfate solution, and connected the anode to the positive terminal and the cathode to the negative terminal. 5. The power supply was turned on and the ammeter passed a current of 1.0A through the cell for 10 minutes. 6. Removed the
Whether the voltage affects the amount of gas produced during the electrolysis of sodium chloride solution.
Electrolysis Coursework Aim An investigation into whether the voltage affects the amount of gas produced during the electrolysis of sodium chloride solution. Prediction When electrolysis of sodium chloride solution takes place there are four ions produced. These are Na+, H+, Cl-, OH-. The sodium and hydrogen are attracted to the cathode but it is the hydrogen given off because it is the less reactive of the two. The half equation for this is H+ +2e›H2. The chloride ion and hydroxide ion will be attracted to the anode because they are both negative but it is the chloride ion that will be given off because it is always the halogen that is given off. The half equation for this is 2Cl- -2e›Cl2. I also predict that increasing the voltage which will increase the current, which will increase the number of electrons flowing which will increase the volume of gas given off. Preliminary When conducting this part of the experiment I started off by trying the experiment on the lowest reading on the power pack which was 0.2v. This was to low as it would take too long to get a good reading so I put it up to 4.0v which was adequate as it only took 30s to get a good reading, so I used 4.0v, 4.2v, 4.4v, 4.6v, 4.8v 5.0v. Diagram Method . Set up equipment as above. 2. Fill a measuring cylinder with water, and invert over the cathode. 3. Set the power pack at the voltage required.
Electrochemistry and electrolysis.
Electrochemistry USING an electric current to produce chemical changes is called electrolysis. It is often used to purify metals and other substances. An electric circuit is set up using two electrodes, an electrolyte (a liquid containing ions), and a source of electricity. When the electricity is on, ions in the electrolyte move towards the electrodes. There, they gain or lose electrons, making them - and the electrodes - chemically different. Chemical changes can also produce electricity. A battery consists of an electrolyte between two different metal electrodes. Chemical reactions occur between the electrodes and the ions in the electrolyte, making electrons flow. PURIFYING COPPER If a current is passed through copper sulphate solution, positive copper ions move from the impure copper anode to the cathode, where they are deposited as pure copper metal. Electrolysis Electrolysis involves the input of a direct electric current, via electrodes, to produce chemical change in an electrolyte. Any electrolyte by definition contains ions that are free to move, and they are therefore normally liquids - either liquid salts, such as molten sodium chloride, or solutions in which ions are dissolved. Copper Symbol Cu Type of Element Transition metal Atomic Number 29 Periodic Table Group 1 Relative Atomic Mass 63.546 Density 8.92 g cm?3 Melting Point ,083.4°C
Can we meet global energy demands just from renewable energy sources?
Can we meet global energy demands just from renewable energy sources? Currently, the majority of our energy comes from fossil fuels. Fossil fuels take millions of years to form. They're a non-renewable resource because reserves are running out faster than new ones are being made. Renewable energy is naturally replenished and comes from natural resources like sunlight, water, wind and geothermal heat. The Sun provides enough energy in one minute to supply the world's energy needs for one year. If this could be harvested then it could mean the end of energy problems in the world. There are two types of solar panels: solar heating panels which heats water into steam which turns a turbine generating electricity and solar cell panels which produce electricity directly. This would be very useful in developing countries. Although the Sun provides us with a lot of energy, in order to harvest this energy a large amount of land would be needed for solar panels. This would include millions of homes and buildings. An advantage of using solar cell panels is that no large scale installation is needed - remote areas can produce their own supply of electricity. A disadvantage of solar heating panels is that there are moving parts that are noisy and require maintenance. Wind turbines use wind to spin turbines which generates electricity. A single large wind turbine could only generate
The Age of the Earth
The Age of the Earth In 1654 it was calculated that the earth had formed on October 23, 4004 BC. James Ussher made this discovery from the Bible. Nowadays the age of the earth is determined to be at least 4.5 billion years old. People all over the world now disagree with Ussher's theory because of religious reasons and most Christians still believe that the Earth was created 4004BC. Almost all of our evidence towards the Earth's age comes from the examination of rocks. People who analyse new discoveries of fossils and meteorites can possibly lead us to knowing the age since we can examine carbon and radiocarbon dating. Fossils in sedimentary rocks and the weathering of most ancient craters prove to us that some of the eldest bits rocks date back to about 4.5 billion years old. There is evidence to prove that the earth had formed approximately 1 billion years ago by radiometric age dating of particular rocks, such as lead in uranium-rich minerals which had showed us that it was in excess of being a billion years old. However the oldest bits of minerals to be discovered are small crystals of zircon that was found at Jack Hills of Western Australia. The dating of these minerals were approximately 4.404 billion years old. The earth must have been as old as any formation on it and information such as this can easily be considered as proof of the earth's existence meaning that
Extracting Copper from Malachite
Chemistry Extracting Copper from Malachite We extracted Copper from Malachite using a displacement reaction. Although electrolysis can also be used. We used 5g of malachite and dissolved it in sulphuric acid; this was to separate the sand and the copper, because the copper dissolves into the solution but the sand remains separate. This was an exothermic reaction. We then filtered the solution to separate the sand from the Copper Sulphate solution. We then dried the sand in order to remove any excess water and weighed it. Then using a displacement reaction we added zinc to the solution (because it is higher in the reactivity series than copper) the solution gradually turned light blue, producing zinc sulphate. After flittering this solution copper was formed. We then weighed the copper. Results Sand = 1.91g Copper Ore = 3.09g Copper = 1.58g % Copper in Malachite = 1.58 5 100 = 31.6% %Copper on Copper Ore = 1.58 3.09 100 = 51.4 Theoretical % CuCO Cu(OH) H 0 2 Cu 63.5 2 = 127 6 O 16 6 = 96 4 H 1 4 = 4 1 C 12 1 = 12 Total= 239 Cu = 127 = 127 239 100 = 53% Evaluation Our plan worked considerably well as we succeeded in extracting copper from its ore. The theoretical percentage is the approximate percentage of Cu that should've been extracted throughout the experiment. So there should have been 53% of Cu extracted. In our experiment
Investigating energy changes during displacement reactions
Investigating energy changes during displacement reactions Aim To find whether the position of a metal in the reactivity series affects how much energy is released during displacement reaction. Introduction A displacement reaction is a reaction with a metal high in the reactivity series, which displaces one below it. For example, calcium could displace iron in a reaction, as it is higher in the reactivity series. (See diagram below). Potassium Most Reactive Sodium Calcium Magnesium Zinc Iron Tin Copper Least Reactive Displacement reactions are exothermic reactions, which means they give off heat when reacted. When a metal is being displaced it means heat energy is given off. Predictions I predict that the reaction of zinc with copper sulphate will have a bigger exothermic reaction than iron with copper sulphate. I think this because zinc and iron are higher up in the reactivity series therefore they displace copper. As zinc is higher up in the reactivity series than iron, so there will be more gas given off by the reaction of zinc with copper sulphate. Apparatus 25cm copper sulphate 2g zinc (powdered) 2g iron (powdered) Measuring cylinder Thermometer Beaker Glass rod Method Measure in a measuring cylinder 25cm of copper sulphate (solution) and pour into a beaker then take the temperature of the solution with a thermometer. Then weigh 2g of iron on
