Record your hypothesis on page 123. -My hypothesis is we can determine the different between each chemical reaction by the temperature change.To descide which one is exothermic and endothermic. 4. Summarize the procedures you will follow to test your hypothesis. -We measured in each chemical and added water besides, HCl we added NaOH.
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.
To perform this experiment, we will utilize emission spectra, titrations, and thermal gravimetric analysis, using knowledge from Experiments 10, 4, Titrations of Na2CO3 and NAHCO3 by HCl (hydrochloric acid) will be performed to determine the concentration of HCl, as well as the number of moles of HCl present within the sample of baking soda. As a result, we will be able to determine the molar concentration of HCl by determining its equivalence point (the point on the graph where the exact amount of rectant needed to perform a reaction has been added) from graphical analysis. Na2CO3(aq.) + HCl(aq.) ==> NaHCO3(aq.)
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.
These tests consisted of a wafting test, a solubility test in deionized water, and a pH test. The unknown’s characteristics, discovered through the physical tests, were then compared with known cations: Sodium, Potassium, Calcium, Ammonia, and Magnesium. Flame tests were performed in order to classify the unknown cation. A small amount of the solid unknown ionic compound was placed on a watch glass. A wet swab was used to collect a small sample of the compound.
Pre Lab Objective: The purpose of this lab is to obtain the mass and volume of two different metal samples, to graph data, to obtain the slope of graphed data and to display a best fit curve of experimental data in order to graphically determine the density of each metal Background: Understanding the relationship that exists between a substance’s mass and its volume. This relationship is expressed by the physical property called density. (D = M/V). In order to determine the volume of solids, a technique called water displacement is used. A fixed amount of water is added to a graduated cylinder and the volume of water is recorded.
Double displacement reaction: Chemical reactions in which one component each of both the reacting molecules is exchanged to form the products. 3. What does the stoichiometry of a chemical reaction mean? Why is it important? Stoichiometry is a section of chemistry that involves using the relationships between reactants or products in a chemical reaction to determine the desired quantitive data.
Observe the color change while it is being heated. After observing the color change, find the mass and moles of the hydrate. Then find the mass and moles of the water eliminated. And lastly find the mole ratio of water to hydrate. For part 2, do the same thing as part 1 except use an unknown hydrate and calculate the percent mass of water in an unknown hydrate.
How do you go from calculated/measured values to accomplishing stated purpose? (4 pts) The purpose of this lab is to determine the exact concentration of an unknown acetic acid solution. Titrations for two different reactions will be performed. Controlled volumes of one reagent are added to a flask containing the other reagent until the equivalence point of the reaction is reached, one between sodium hydroxide (NaOH) and potassium hydrogen phthalate (KHP) and the other between NaOH and acetic acid (CH3COOH). NaOH (aq) + KHP (aq) —› Na+ (aq) + K + (aq) + P2- (aq) + H2O (l) NaOH (aq) + CH3COOH (aq) —› Na+ (aq) + CH3COO- (aq) + H2O (l) The titration of NaOH with KHP will identify the concentration of the NaOH provided.
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