Therefore there is an average rise in temperature; energy is lost which results in a negative ?H. The outcome variable for this experiment is to conclude what changes can be made to vary the heat energy when magnesium is reacted with sulphuric acid. Magnesium + Sulphuric Acid ¡ú Magnesium Sulphate + Hydrogen Mg (s) + H2SO4 (a) ¡ú MgSO4 (a) + H2 (g) There are many variables which can be changed in some way to effect the reaction, some of which are listed below:- Volume of Sulphuric Acid Concentration of Sulphuric Acid Initial temperature of Sulphuric Acid Motion of liquid (speed of stirring) Amount and size of magnesium Purity of magnesium The extent of oxidation on the surface of the magnesium Addition of Catalysts Size of Container Temperature of surrounding environment Pressure at which reaction is conducted Insulation of the test-tube Height of thermometer above the base of the test-tube Explaining variables In solutions of higher concentration, particles are closer together. They have a greater chance of colliding. Because there are more collisions the reaction rate is greater.
23/04/14 (http://chemwiki.ucdavis.edu/Physical_Chemistry/Thermodynamics/State_Functions/Enthalpy) When the reaction is giving off heat, it is exothermic. In this case, the enthalpy change is negative, since the reaction is going from high energy to low energy due to the loss of heat energy to its surroundings. If energy flows from the surrounding environment and heat is being taken in, it is endothermic. The change is positive as the system is gaining energy in the form of heat. Bond Making and Bond Enthalpy Bond enthalpy is the energy that is required to break a chemical bond.
Literature review: 1. Introduction: In ingot casting the molten metal is poured in the mold to get solidified ingot where liquid metal transformed to solid metal. So the poring temperature of the molten metal is very important parameter. Poring temperature is the initial temperature of the molten metal used for the casting ingots as it is poured. So this poring temperature will obviously be higher than the solidification temperature (i.e., higher the liquidus line) of the metal.
Investigation of the Thermal Decomposition of Copper Carbonate Aim: Copper has two oxides, Cu2O, and CuO. Copper carbonate, CuCO3 decomposes on heating to form one of these oxides and an equation can be written for each possible reaction Equation 1: 2CuCO3 (s) Cu2O (s) + 2CO2 (g) + O2 (g) Equation 2: CuCO3 (s) CuO (s) + CO2 (g) The aim of this experiment is to prove which equation is correct. This can be done by volumetric analysis i.e. calculating the volume of gas produced. This is then compared to the calculated volume of gas produced in each equation and the equation with the nearest volume of gas is correct.
Since pentane only has weak dispersion forces it evaporated much faster once the probe was taken out of the test tube and had a higher change in temperature. Figure 3 illustrates the change in temperature during evaporation for the alcohol methane and the alkane hexane. The ... ... middle of paper ... ...ces and high molecular weights make a substance harder to evaporate, while weak intermolecular forces and low molecular weights make it easier to evaporate, resulting in a change in temperature that was either low or high. Possible errors that could have occurred during the experiment could be from incorrectly calibrating the temperature probes at the start of the experiment, which would throw off the temperature readings and make them too high or too low. Another error could have come from starting the data collection too late and missing the beginning of the evaporation, thus resulting in a maximum temperature that was too low and a change in temperature also too low.
How does temperature affect the rate of reaction between sodium thiosulphate and hydrochloric acid? Temperature and Rate of Reaction Question How does temperature affect the rate of reaction between sodium thiosulphate and hydrochloric acid? sodium thiosulphate + hydrochloric acid sodium chloride +water + sulphur dioxide + sulphur Na2S2O3(aq) + 2HCl(aq) 2NaCl(aq) + H2O(l) + SO2(aq) + S(s) Prediction I predict that the higher the temperature, the more quickly reaction will occur. This is because with heat, the particles of sodium thiosulphate and hydrochloric acid have more energy. This causes them to move around more.
To further understand this topic, future research could include; how does the amount of liquid incorporated affect the corrosion rate, how does the temperature of the liquid affect the corrosion rate, and how does the purity of iron affect the corrosion rate? Prior Research Elements, corrode when in proximity with liquid; water and oxygen, these compounds and elements are mandatory for corrosion to occur. Corrosion is a result from oxidation; when an element corresponds with oxygen. For example when the element;... ... middle of paper ... ...the corrosion rate, then the lower the pH level is, the quicker the corrosion rate would be. This will happen because if the pH level of a liquid is lower, the hydrogen ions will consume the electrolytes, hydrogen ions are also being consumed and the element starts corroding faster.
Fractional Distillation of Crude Oil BOILING POINTS AND STRUCTURES OF HYDROCARBONS The boiling points of organic compounds can give important clues to other physical properties. A liquid boils when its vapor pressure is equal to the atmospheric pressure. Vapor pressure is determined by the kinetic energy of molecules. Kinetic energy is related to temperature and the mass and velocity of the molecules. When the temperature reaches the boiling point, the average kinetic energy of the liquid particles is sufficient to overcome the forces of attraction that hold molecules in the liquid state.
In this experiment there are a few factors that can affect the results of the experiment. These factors can make the results of the experiment be incorrect. The factors that can affect the experiment are: 1 Water 2 Amounts of powder 3 Distance the flame is away from the metal carbonate Water can affect the results because it can get into the powder, which can speed up a reaction. If different amounts of the substance are used, then the results can be affected because the more amount of powder there is, the more carbon dioxide will be produced. Plan In this experiment I plan to use 1/500 of a mole.
When breaking bonds it requires energy, which means it's a endothermic reaction because the heat in the surrounding is absorbed to break the chemical bond. When making bonds it gives out energy due to the reaction that has been taken place and means that it's an exothermic reaction. Every reaction that happens will either give out energy or take in energy due to the type of reaction. The reason for this is because it needs the energy or gives out the energy. To tell weather it is an exothermic or endothermic reaction a thermometer can be used to indicate what type of reaction it is.