The reason why we're determining if their was a chemical reaction is to identify if it is exothermic or endothermic. How exactly we do is that ionic compounds dissolve in water ,or HCl, to break down the ionic bonds. With these ions it attaches to the water molecules and
The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies. There is an equation to determine how much of this heat energy is lost or gained when a reaction is performed. Q = c m (T1-T2) Where: q is the energy in Joules C is the heat capacity, measured in joules per gram per degree Celsius M is the mass of the solution, measured in grams J is the joules G is the grams of water T is the temperature ΔH=ΔE + PΔV = (q p +w) – w = q p Procedure: 1. Follow instructions 1-9 in Appendix A-1 to initialize the MeasureNet workstation. a.
The salt crystal is made of positive and negative ions that hold the it together (eg. NaCl or Na+ and Cl-) by electrostatic ion-ion attractions (the attraction of opposite charges). When a salt dissolves in water, the electrostatic attractions between the ions are broken and each ion forms new electrostatic interactions with the water molecules (see figure 1). Whether this process creates an endothermic or exothermic reaction depends on the balance between the ion-ion forces of the solid salt that must be overcome and the dipole-ion forces that stabilize the dissolved ions in solution. Purpose In this experiment, you will be able to: o Distinguish between the terms: exothermic and endothermic reaction.
Water from a variety of sources that receive precipitation is being sampled. Using a pH meter, the pH of water samples is being measured. In the first approach using titration methods in combination with pH measurement, the volumes of sulfuric acid needed for reaching two different pH levels are being measured. Difference in the volume of sulfuric acid used, is an equivalent for the amount of CaCO3 expressed in grams per (gL-1) in the analyte. Therefore the alkalinity of water samples is being calculated.
Calculations involving the Mole, Avogadro’s Number, Molar Mass, Mole-Mole and Mass-Mole calculations in chemical equations. Combustion analysis and calculation of empirical and molecular formulas from composition analysis. Electrolytes and non-electrolytes. Precipitation reactions and solubility rules. Writing balanced molecular equations and net ionic equations.
3) Write equations to indicate what you consider to have happened in each case in which there was precipitate formed. Use ions to represent the species in the reacting solutions, but for those products that were precipitates write a formula for the compound. Place (aq) after those species in solution and (s) after the precipitates. Be sure to write the equations so that both atoms and charge are conserved. For example: Ag+(aq) + NO3-(aq) + Na+(aq) + Cl-(aq) ( AgCl(s) + Na+(aq) + NO3-(aq) 4) Rewrite the equations, leaving out the ions not involved in the reaction (spectators).
To find out N2 you have to determine the mass of water produced in the reaction. This mass is the difference between the mass of initial compound (BaCl2•XH2O) and the mass of anhydrous salt (BaCl2). N2 is the ratio of the mass of the water produced in the reaction to the molar mass of
Final Essay Exam GEOL 108 1. Describe the paths of water through the hydrologic cycle. Explain the processes and the energy gains and losses involved in the changes of water between its 3 states. Operationally, we often most concerned with water does when it reaches the solid earth, both on the surface and in the sub-surface. Explain the relationship between the saturated zone, the water table, a ground water well and the cone of depression, all within the sub-surface.
The dependant variable of this experiment will be the rate of reaction of the enzyme catecholase with its substrate catechol. The independent variable of this experiment is the various pH levels that the catecholase and catechol are exposed
Protein phosphorylation is one type of post-translational modification. * Activate proteins Understand what is meant by membrane potential What is an electrochemical gradient? What does it do in active transport? How? Understand the two forces at work in an electrochemical gradient What is an electrogenic pump?