Uses and Properties of Sodium Hydroxide

3ml of sample was taken first flask at 4 minutes and added to the appropriate tube of sodium hydroxide, from the second flask at 4.5 minute and so on, each flask was sampled at 30 second intervals. The sampling was then repeated starting at 8,12,16 minutes. The final sample from the last flask was taken at 18.5 minutes. Once the sampling was completed, measurements of absorbance were obtained for solution in each tube at 405 nm.

The type of cold pack presented here contains ammonium nitrate, which is a white crystalline substance. When these crystals react with water they split into positive ammonium ions and negative nitrate ions. Due to the energy expended by the water in order to dissolve these crystals, the water becomes colder.

4. NaOH, sodium hydroxide is a strong base. It reacts with HCl and forms NaCl and H2O.

Nitric acid has the chemical formula HNO3, a molecular weight of 63.01 grams/mol, a melting point of -42 °C, and a density of 1.5027 grams/mL. (PubChem.com)

The purpose of this experiment was to find the amount and percent of water in a hydrated salt. Hydrated salt contains water molecules chemically bound to it while anhydrous salt is a substance that fire can readily remove the water molecules. Using the gravimetric analysis method, the sample salt was measured, heated, and was measured again after cooled down to room temperature; this procedure allowed the weight of water lost in the salt to be obtained. After two trials, the water in the salt was determined to have an average percent water of -35.04%. The null hypothesis, the heat will not affect the amount of water lost, was rejected ,however, the alternative hypothesis, the heat will allow for there to be water lost, was not supported.

Introduction: The concentration of Hydrogen Ions in a substance is its pH. Hydrogen Ions (H+), and Hydroxide Ions (OH-) are formed when an electron jumps from one H2O atom to another. When a Hydrogen Ion is in an aqueous solution (a solutions with water as the solvent) it bond with an H2O atom creating H3O also known as Hydronium. A substance with more Hydrogen Ions than Hydroxide Ion is called a base. A substance with more Hydroxide Ions than Hydrogen Ions is called an acid. This can be seen on the pH scale below (Figure 1). A pH scale shows the number of Hydrogen

Materials: Solutions of crystal violet and sodium hydroxide were available in the laboratory which were previously prepared of concentrations 2.00 E-5 and 2.00 E-2 respectively. Deionized water was used

The pipet was put into the top of the condenser and leaving no open spaces. The vacuum served to get rid of the nitrogen oxide gases that were formed during the oxidation reaction. The solution was heated for 30 minutes, beginning the time when the first sign of nitrogen oxide fumes were observed. After the 30 minutes, the solution was removed and cooled for a few minutes. The solution turned was a brownish-yellow color and all the crystal were dissolved, leaving a liquid. The solution was then transferred, using a Pasteur pipet, to 3 mL of water in a beaker. The reaction flask was rinsed to remove the remainder of the solution. The solution was stirred with a glass rod until room temperature of the solution was achieved. A yellow solid was to form, but instead the solution remained aqueous in the case of the specific experiment explained here. With additional scraping of the solution with a glass rod, no crystals formed at all. The next procedure, if the crystals had formed was to crush the solid with the glass rod and filter the solid until the crystals were dry. The mass would then be weighed and the crystals were to be recrystallized with 95% ethanol. The crystals were to be cooled in ice water to get full crystallization and then the crystals were to be filtered and air dried, then weighed.

A hot plate was placed on a ring stand with a 50 mL beaker being placed on a hot plate. The ring on the ring stand was positioned to surround the beaker. Rubber tubing, a funnel, and an aspirator was then used to make an aspirator, with the funnel placed over the beaker connected to the aspirator. The HNO3 used in Step 1 will give off toxic gas, which the funnel will prevent from spreading away from the beaker. 250 mg of copper was weighed and transferred into the 50 mL beaker. 5 mL of M HNO3 was poured into a 10 mL graduated cylinder. The aspirator was turned on by starting the water and 4 mL of HNO3 was added to the beaker and slowly heated with the hot plate. After the reaction occurred the aspirator was turned off and 10 mL of distilled water was added to the beaker. 6 M NaOH was added in drops to the solution and stirred with a stir rod while periodically

When sodium carbonate was added to the separating funnel, effervescence occurred, inferring the release of carbon dioxide gas as a product of the neutralisation reaction. As the process continued, pressure built within the separating funnel, so it was vital to open the tap, after continuously inverting it.

This liquid is clear, has a fluid consistency similar to water, and has a strong odour that reminds me of alcohol.

As seen at the equations, the solid NaOH dissociates into its ions, after that it is neutralized by HCl.

Experiment to investigate the amount of sodium hydroxide needed to neutralize the solution of vinegar

Once cooled, the mixture was then transferred to a separatory funnel using the funnel while avoiding adding the boiling chip. 10 ml of water was then added to the mixture. The mixture was gently shaken and the phases were allowed to separate. The funnel was then unstopped and the lower aqueous phase was drained into a beaker. 5 ml of 5% aqueous NaHCO3 was added and then shaken gently. A great deal of caution was taken into consideration because of the production of carbon dioxide gas which caused pressure to develop inside the funnel. The pressure needed to be released so the funnel was vented frequently. The phases were allowed to separate and the lower aqueous phases was drained into the beaker. After draining, 5 ml of saturated NaCl was added to the funnel and then shaken gently. Once again, the phases were allowed to separate and the lower aqueous phase was drained into a beaker. An ester product was produced and was transferred into a 25 ml Erlenmeyer flask. This organic product was then dried over anhydrous Na2SO4 to trap small amounts of water in its crystal lattices thus removing it from the product. Finally the ester was decanted, so that the drying agent was excluded from the final product.

This experiment was performed to determine the heat of neutralization between Hydrogen chloride (HCl) and Sodium hydroxide (NaOH). A temperature probe was used to measure the temperature of the reaction when the base (NaOH) was poured into the acid (HCl). The data was collected on logged on LoggerPro.