When potassium nitrate is placed in water the slightly positive hydrogen’s in the water molecule are attracted to the nitrate ions and the potassium ions are attracted to the slightly negative oxygen. Figure 1 shows how sodium chloride would bond when placed in water. Figure 1 Sodium chloride dissolved in water (Adams, R. et al, 2011) The solubility of a solute in a solvent is affected largely by the temperature. A solubility curve (as seen in Figure 2)
Is There a Change in Temperature when an Alkali Neutralizes an Acid? Aim The aim of the experiment was to find out if there was a change in temperature when we added an alkali (Sodium Hydroxide) to an acid (Hydrochloric Acid) to neutralize it. Hypothesis We hypothesized that there was going be a raise in temperature as we add 1ml of Sodium Hydroxide at a time to the Hydrochloric Acid due to the neutralization of the acid. The neutralization is chemical reaction that causes an exothermic reaction. Sodium Hydroxide + Hydrochloric Acid Sodium Chloride + Water NaOH(aq) + HClaq → NaCl(aq) + H2O(l) Variables Independent The independent variable of the experiment was the amount of sodium hydroxide that we added to the acid.
Chemistry 3/19/13 Calorimetry Lab Report Purpose: Calorimetry is the measurement of the heat flow into or out of a system for chemical and physical purposes. The purpose of this lab was to use calorimetry to find how much heat is absorbed or released when NaCl is dissolved in water. In this case, we will find the heat coming out of the system, in a chemical process. Hypothesis: Once the sodium chloride is put into the water, the temperature of the water will rise. Procedure: 1.
Now to find this we would also have to look at the heating curve of the experiment. Also we have to look for when and how the physical change from a solid to a liquid (melting) happens to the Lauric Acid. * A heating curve is when you supply heat to an isolated material over a certain amount of time. To see the heating curve you must graph to noticeable see the rise and stabilization of the heat within the material. Also to further example this lab, Phase Change is when one state of matter changes to another state of matter through either endothermic or exothermic change.
A1. a Chemical equilibrium is ‘dynamic’ because both forward and reverse reactions occur at the same rate. An equilibrium develops between water vapour and water when wet clothes are in a sealed bag, with water evaporating as rapidly as water vapour condenses, so the clothes remain wet. b When the bag is opened, water vapour escapes and the rate of evaporation exceeds the rate of condensation. The system is not in equilibrium and the clothes dry.
The rate law for this reaction is rate = k[acetone]m[H+]n[I2]p where k is the rate constant for the reaction and m, n, and p are the orders of the reaction with respect to acetone, hydrogen ions (acid), and iodine, respectively. Although orders of reaction can be any value, for this lab we will be looking only for integer values for the orders of reaction (0, 1, 2 are acceptable but not 0.5, 1.3, etc.) The rate of the reaction can also be expressed as the change in the concentration of a reactant divided by the time interval: rate = - Δ[ I 2 ] Δt The iodination of acetone is easily investigated because iodine (I2) has a deep yellow/brown color. As the acetone is iodinated and the iodine converted to the iodide anion, this color will disappear, allowing the rate of the reaction to be easily monitored. We can study the rate of this reaction by simply making I2 the limiting reactant in a large excess of acetone and H+ ion.
Define also the overall order of a reaction and describe how it’s found. Explain how the iodine clock reaction works and the method it employs to find the order of a reaction with respect to a particular reactant. Experimental: Apparatus: 3 -100 cm3 beakers, 1 thermometer, 0-100 0C, 8 burettes with beakers and funnel for filling, clamps and stands, stop clock or watch. Reagents: Potassium peroxodisulphate (VI) solution [0.100 mol dm-3 and 0.050 mol dm-3 K2S2 O8], Potassium iodide solution, [0.500, mol dm-3 and 0.250 moldm-3, KI], Sodium thiosulphate solution, [0.010 mol dm-3 Na2S2O3], Starch solution, 0.2% Procedure: 1. Using a burette, run 5.0 cm3 of 0.100 mol dm-3 peroxodisulphate solution into a 100 cm3 beaker.
Whether the strength of Hydrochloric acid will affect the speed of the rate of reaction when reacting with Magnesium Ribbon. I want to find out whether the strength of Hydrochloric acid will affect the speed of the rate of reaction when reacting with Magnesium Ribbon. Variables There are two important independent variables in my investigation the first of which is the concentration of the Hydrochloric Acid used during the investigation. The concentration of the acid will partly determine how fast the reaction takes place, if we put some of the magnesium ribbon into the HCL at 2molar then it might have simply dissolved within a few seconds and then I would not have had time to record down any decent enough results to plot a graph with. The other important independent variable that will affect the speed of the rate of reaction is the length of magnesium ribbon.
The boiling point can be reduced because of the vapour pressure of it would be the sum of water’s vapour pressure and the compound’s vapour pressure. (http://www.brynmawr.edu/chemistry/Chem/mnerzsto/steam_distillation.htm) According to this experiment, A here is the water and B is the clove. Because liquid boil in atmosphere pressure, so with the existence of water that have boiling point at 100ᵒC, the atmosphere pressure could be reached sooner. The solution resulted from the distillation in this experiment was extracted. To do extraction,
The indicator Phenolphthalein was the substance used to signal when the titration reached the point at which the reactants are stoichiometrically equal as defined by the balance reaction equation. Phenolphthalein is a chemical compound with the formula C₂₀H₁₄O₄ and is often written as "HIn" or "phph" in shorthand notation. Often used in titrations, it turns colorless in acidic solutions and pink in basic solutions. Sodium hydroxide or Hydrochloric acid would not have been as effective or accurate because they would have reacted with the water vapor from the air. In this lab setup, graduated cylinders or beakers were not used.