If the reaction is first order, its graphical representation is seen as ln[A] (natural log of concentration) vs. time, and the slope of its like is also the negative rate constant. Finally, for a second order reaction the graph is shown as 1/[A] (inverse of concentration) vs. time, and the slope of its given line is the positive rate constant. By understanding the rate law and finding the value of the correct rate constant with respect to the order of the reaction, one can determine the half-life of the crystal violet. This is because the crystal violet undergoes a decay reaction with the sodium hydroxide. According to Beer's Law, the absorbance of crystal violet is proportional to its concentration.
Rajeev Pathapati Limiting Reactant Lab Chemistry 6th Due: 2/9/12 Introduction: When a chemical reaction occurs, there is usually a limiting reactant. In a chemical reaction, the limiting reactant, also known as the limiting reagent, is the reactant that is totally consumed at the end of a chemical reaction, and is the reactant that limits the amount of product formed. This also results in excess of the other reactant(s). The reaction tested in this experiment was between a Copper (II) Chloride aqueous solution, and Aluminum metal. The purpose of the lab was to determine which reactant was the limiting reactant, and to see how much of the other reactant was used.
The purpose of this lab was to find the molecular weight of two unknown substances by analyzing the freezing points in cyclohexane and to provide a visual representation of the freezing point depression effect. The theory of this lab is; by using measurements of mass of the unknown substances (solute) in correlation with the mass of the cyclohexane (solvent) and the freezing point constant of the solvent, you could determine the molecular weight of the solute by using the same math involved in deciding the freezing point of the solution/ The theory behind the visual of the FPD effect is that if one was to record the freezing point of a solution and two solutions of the same substances with more solute, one would see a visible drop in freezing point. The equations you needed for this lab were the freezing point formula for organic substances (ΔFp=(m)Kf) and the
For that we must put the temperature we found and put it into 1.01(x) + 4.43. 1.01 multiplied by 31.8 plus 4.43 equals 36.59 degrees Celsius. Now that all of our values are ready to be analyzed we can narrow down what the unknown substance is. I started with boiling point there was only 2 substance had a boiling point close to the boiling point that we found pentane and ethyl ether. Next the freezing point which didn’t eliminate either of them.
Hydrate Lab The purpose of this lab is to analyze the percent water in a crystalline hydrate and to indentify the hydrate from a list of possible unknowns. The solid hydrate will be heated to remove the water, and the percent can be found by measuring the mass of the solid before and after heating. The hydrate will be indentified by comparing the percent water in the hydrate with the percent water calculated for the possible unknown. Before the lab there are pre-lab questions: 1. Describe the three general safety rules for working with a Bunsen burner.
Therefore, according to Hess’s law, the heat of reaction of the one reaction should be equal to the sum of the heats of reaction for the other two. This concept is sometimes referred to as the additivity of heats of reaction. The primary objective of this experiment is to confirm this law. The reactions we will use in this experiment are: 18 - 1 Computer 18 You will use a Styrofoam cup in a beaker as a calorimeter, as shown in Figure 1. For purposes of this experiment, you may assume that the heat loss to the calorimeter and the surrounding air is negligible.
1) Jeffrey Cox CHE111-DL01 Lab number 10 Stoichiometry of a Precipitation Reaction 2) Purpose/ Intro. In this lab we will be able to calculate the actual, theoretical, and percent yield of the product from a precipitation reaction. We will thusly learn the concepts of solubility and the formation of a precipitate. A precipitate reaction is a reaction in which soluble ions in separate solutions are mixed together to form an insoluble compound that settles out of the combined solution as a solid. The solid then is the insoluble compound, called a precipitate.
This table shows the data collected while standardizing NaOH. With finding the volume used/ final volume. Trials | Mass of KHPthl (g) | Initial volume (mL) | Final volume(mL) | Volume used(mL) | 1 | 1.02 | 0.00 | 36.10 | 36.10 | 2 | 1.01 | 0.00 | 38.5 | 38.5 | 3 | 1.00 | 0.00 | 39.1 | 39.1 | Potassium hydrogen phthalate is used for standardizing NaOH because it is slightly acidic, which is often used with NaOH and is used as a buffering
Experiment 1 Freezing Point Depression of Electrolytes Colligative properties are properties of solutions that depend on the concentrations of the samples and, to a first approximation, do not depend on the chemical nature of the samples. A colligative property is the difference between a property of a solvent in a solution and the same property of the pure solvent: vapor pressure lowering, boiling point elevation, freezing point depression, and osmotic pressure. We are grateful for the freezing point depression of aqueous solutions of ethylene glycol or propylene glycol in the winter and are continually grateful to osmotic pressure for transport of water across membranes. Colligative properties have been used to determine the molecular weights of non-electrolytes. Colligative properties can be described reasonably well by a simple equation for solutions of non-electrolytes.