If the product was water this would create the new bonds from oxygen and hydrogen atoms. Bond formation releases energy- just like letting a spring go. A chemical reaction is decided by exothermic or endothermic it is the difference between the energy taken in to break bonds and the energy given out as a new bond form. C:\Documents and Settings\11JAnd01\Local Settings\Temporary Internet Files\Content.IE5\3DZQD5EO\Picture1[1].gifEndothermic- Endothermic is when the experiment you’re doing is taking energy from its surroundings. Exothermic- Exothermic is when the experiment you’re doing is giving energy out to its surroundings.
The Solubility of Potassium Nitrate Introduction The purpose of this experiment was to observe how temperature affected the solubility of solid potassium nitrate that was put in different solvents. The temperature was not the other thing that was being varied to observe the solubility of potassium nitrate, the amount solute was also varied and the kinds of solvents in this experiment were varied. The nature of each solvent changes due to the common ion effect which is basically means that the concentration of a soluble salt is reduced if there is a common ion with that salt. Also potassium nitrate solubility in basic and acidic places was also determined, to see if it affected the temperature. The moles of KNO3 s/ Kg solvent were needed to calculate the correct molal concentration.
One of the applications of Hess' Law is to determine the enthalpy change for a reaction by combining other reactions to get the desired reaction, then combining the enthalpy changes for the reactions to get delta H for the reaction under consideration. An exothermic enthalpy change is always Assessed Practical: Planning Introduction: The aim of this experiment is to find the enthalpy change for the decomposition of sodium hydrogen carbonate. 2NaHCO = Na2CO3 + CO2 + H2O Using the enthalpy change of the following reactions. Sodium Hydrogen Carbonate: NaHCO3 + HCl = NaCl + CO2 + H2O Sodium carbonate: Na2CO3 + 2HCl = 2NaCl + CO2 + H2O Apparatus Sodium hydrogen carbonate Sodium carbonate Polystyrene Cup x 2 Measuring cylinder 50cm³ x 2 Weighing scale Weighing boats Thermometer degrees Spatula HCl acid 2M Prediction Background Information Hess' Law states that the enthalpy change for a reaction is the same whether the reaction occurs directly or in steps. This is a direct consequence of the fact that enthalpy, is a state function.
After mixing, the temperature of the water is 60°C. (a) How much did the temperature if the hot water change? How much did the temperature of the cold water change? (use positive and negative signs) ∆Twater=Tfinal-Tinitial=(60℃-20℃)=+40℃=cold water ∆Twater=Tfinal-Tinitial=(60℃-80℃)=-20℃=hot water (b) During the mixing, how did the heat transfer? From hot to cold or cold to hot?
Phenolphthalein) is used to show the equivalence point has reached by changing colours. Titration experiments are used to determine the concentration of an acid or a base, if either acid or base concentration known, the other unknown concentration can be find out by measuring how much it takes to neutralize, which is a useful experiment. The Bronsted-Lawry theory about acid and base, describes as follows; an acid a proton (hydrogen ion) donor, a base is a proton (hydrogen ion) acceptor, or any component that can transfer proton to any other component is and acid and any component that accepts the proton is base. The theory says a substance can function as an acid only when a base is presented, and also other way round, a substance can only function as a base in the present of an acid. This theory consider a large
Sweat is made up mostly of water but also contains minerals, urea, lactic acid, ammonia and sugar. Sweating is your body’s way of keeping body temperature at the norm of 37°C. When you run long distances or exercise in hot weather, for example, your muscles exert themselves and your body overheats. Sweating is your body’s way of bringing your temperature back to normal. How our body maintains a constant temperature Temperature receptors in the skin detect changes in the external temperature of the body.
Chromite is iron magnesium chromium oxide. In some rare cases, magnesium is substituted for iron. Also aluminum and ferric ions can substitute chromium in a reaction. Hydrometallurgy is a form of extractive metallurgy that utilizes aqueous solution chemistry for the recovery of metals from salts, minerals, or ores. Extraction is a process in which metal is removed from an ore by dissolving the metal in a solvent, then recovering the metal from the solution (This is done by dissolving the metal into an acid or water).
This reaction is carried out by adding a solution of reactant hydrochloric acid from a burette to a solution of sodium hydroxide until just sufficient of hydrochloric acid has been added to react with all of the sodium hydroxide. If the concentration and volume of hydrochloric acid is known the number of moles of sodium hydroxide can be calculated, if the equation for the reaction is known. This procedure is known as a titration and the point at which sufficient volume of hydrochloric acid has been added to the sodium hydroxide to complete the reaction is called the end point. An indicator which changes colour at the equivalence point is often used to indicate the titration end point. This standardized solution of sodium hydroxide can then be used to determine the concentration of acid in the sample of gastric juice.
If you spill acid on yourself, immediately flush the affected area with water for 2-3 minutes and notify the teacher. If acid should get into your eyes, begin flushing with water immediately and continue doing so for at least 20 minutes. If there is an eye wash fountain equipped with continuously running water in the laboratory, use it. If acid is spilled on the laboratory bench or on the floor, neutralize the spill with solid sodium bicarbonate, NaHCO 3 , before wiping it up with sponges or
The hunter process follows the same steps as the Kroll process except for the fact that sodium is added to the vessel and therefore, NaCl is the salt that is entrapped in the pores of the sponge formed. The chemical equation for the hunter process is as