Our result would have been clearer to observe if we centrifuged it long enough because we might have lost some of the precipitate while washing it since it was not centrifuged long enough. 4. Answer the post lab questions: a. Zn + I2 + H2O Zn(OH)2 + I2 b. Zn(OH)2 + CH3COOH Zn(O2CCH3)2 c. A side reaction is an unwanted chemical reaction taking place that diminishes the yield of the desired product. d. In the synthesis of Zinc iodide, acetic acid was used because the aim of the experiment was to derive Zinc iodide. If we used water instead of acetic acid then zinc would have reacted with water and become Zinc hydroxide which would hinder our purpose.
An aqueous solution of ammonium sulfate is allowed to react with an aqueous solution of lead(II) nitrate. Identify the solid in the balanced equation. A) (NH4 )2 SO4 B) Pb(NO3 )2 C) PbSO4 D) NH4 NO3 E) There is no solid formed when the two solutions are mixed. ____ 11. An aqueous solution of sodium carbonate is reacted with an aqueous solution of calcium chloride.
Since vinegar is an acid, you know that vinegar was not in the solution and it must be something else. You decided to investigate if the new wave of Vitamin Water is pH neutral: neither too acidic nor too basic. Using BTB (bromothymol blue), you select five flavors of Vitamin Water to rest. Three of the flavor-samples turn a murky green, indicating the likelihood of acid/base balance. Of the two remaining, one turns slightly yellow, while the other remains blue.
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.
It binds with starch so the more starch, the darker the solution was. We also used a blank solution with no starch to set the spectrometer to zero. The spectrometer was used to compare the absorbency of the starch in the control solutions and the non-control solutions over time. Amylase was the last solution added to start the initial breakdown of the starch. Adding it at one minute intervals allowed the students to see how much starch the amylase was actually breaking down over time.
Computer Additivity of Heats of Reaction: Hess’s Law 18 (1) Solid sodium hydroxide dissolves in water to form an aqueous solution of ions. (2) Solid sodium hydroxide reacts with aqueous hydrochloric acid to form water and an aqueous solution of sodium chloride. NaOH(s) + H+(aq) ) + Cl–(aq) → H2O(l) + Na+(aq) + Cl–(aq) ∆H2 = ? OBJECTIVES • • • • In this experiment, you will Combine equations for two reactions to obtain the equation for a third reaction. Use a calorimeter to measure the temperature change in each of three reactions.
Different compounds boil at different temperatures because each has a different, characteristic vapor pressure: compounds with higher vapor pressures will boil at lower temperatures. Boiling points are usually measured by recording the boiling point (or boiling range) on a thermometer while performing a distillation. This method is used whenever there is enough of the compound to perform a distillation. The distillation method of
Tablet | A report based on a scientific experiment designed to investigate and compare the rates at which different forms of aspirin dissolve. | 11-11-2013 | Introduction This experiment was designed to investigate and compare the rates at which different aspirin tablets dissolve in both Water (H2O [representing saliva]) and Hydrochloric Acid (HCl [representing the stomach’s acid]). The amount of Water and Hydrochloric Acid will be kept constant between tablets, and tests. Aim To investigate and compare the rates at which different Aspirin Tablets dissolve. The different kinds of Aspirin tablets are: * Enteric Coated Tablets * Capsules * Regular Tablets * Dissolving Tablets.
The heat obtained when a known mass of alcohol or paraffin wax burns will be used to warm a measured volume of water. Enthalpy change can be defined as the amount of heat released or absorbed when a chemical reaction occurs at constant pressure. In an exothermic reaction, such as the case in this experiment, the following reaction takes place: H = H(products) - H(reactants) = negative (-ve) Specific heat is the amount of heat per unit mass required to raise the temperature by one degree Celsius. The relationship between heat and temperature change is usually expressed, where c is the specific heat. The relationship does not apply if a phase change is encountered, because heat added or removed during a phase change does not change the temperature.
[2] A saturated solution is one that holds as much dissolved solute as possible at a given temperature, therefore only a small amount of a slightly soluble ionic compound is needed to produce a saturated solution of that compound. [2] The solubility of a salt is the amount of the salt that