Synopsis This experiment is the determination of Calcium Carbonate (CaCO3) content in toothpaste with the use of back titration while demonstrating quantitative transfer of solids and liquids. A accurately weighed quantity of toothpaste was dissolved in excess volumes of HCl. This solution is then titrated with NaOH to find the volume of the excess HCl. The volume of HCl reacted, which is found by substracting the volume of given HCl with the volume of excess HCl reacted, can be further manipulated with mole fractions to find the mass of CaCO3 and thus the CaCO3 content in toothpastes. Results show that an average of 22.5% CaCO3 is found in toothpaste.
After thoroughly mixing, the content was transferred into a ring-type glass holder and covered with a filter paper. The mixture was left undisturbed until the organic solvent evaporates through the filter paper. The polymer membrane with a uniform surface was formed after 24 hours and its thickness was approximately 300µm [4, 13]. PVC/DOA/yolk membrane was prepared by the same procedure above except with an inclusion of egg yolk as an electro active material. The content of a single egg was transferred into a glass bowl such that the yolk and white remains separated.
In order to synthesize this compound, measure out 1 gram of NaC2H3O2.Weighed 1 gram of NaC2H3O2 and mixed it with ionized water. Boiled 12 mL of 1.0M Acetic Acid added into a beaker containing the sodium carbonate on a hot plate until all the liquid is evaporated leaving solid precipitate form inside of the beaker. Weigh the precipitate form and mix it with water until fully dissolved. Weigh the precipitate remaining. A flame test and a halide ion test were performed.
A practical way to check the pacifier for your newborn is the following: Put milk in the bottle and turn it over. Normally they should come in drops rapidly. If the milk runs like water from a faucet then the hole is too big. Contrary to milk does not run then the hole is too
Baking soda is used to prepare antacid that neutralise the acid in stomach. It is also used in soda-acid fire extinguisher. Washing soda is chemically known as Sodium carbonate decahydrate (Na2CO3.10H2O). When sodium hydrogen carbonate is heated, anhydrous sodium chloride is obtained, which when dissolved in water and recrystallised, forms washing soda. 2NaHCO3 Heat Na2CO3 + CO2 + H2O Na2CO3 + 10H2O Recrystallisation Na2CO3.10H2O Washing soda is used in the manufacture of glass, soaps and paper.
This weight was recorded to four significant figures. After this, piece of magnesium was wrapped around the tip of copper wire. Following this, the buret was filled with about 10.0 mL of concentrated HCL and water was added until the buret was full. The copper wire with the magnesium was then putted into the buret and held in place with the rubber-stopper to make sure the copper wire wouldn't fall to the bottom. Distilled water was pure into the rubber-stopper to make sure the buret was completely filled and to make sure there wouldn't be any bubble.
To acquire precise results, it was assured that no water splashed outside the dish while shaking. Moreover, in this step, at least two-thirds of the paper did not stick within itself or folded, to ensure similar outcome was obtained each trial. The swinging process was implemented to duplicate situations where the tissue used to clean the mess on a table has to be carried to a garbage can without dribbling on the floor. After swinging, the amount of water left in the glass plate was
Rinse out all the oxalic acid crystals with the wash bottle from the funnel in the volumetric flask. 12. Add deionized water to the volumetric flask to the 250ml mark on the volumetric flask. 13. Read the volume from the bottom of the meniscus.
Wash ether layer with saturated sodium chloride solution and retain ether layer. In a small 125ml Erlenmeyer flask, dry the ether solution over anhydrous calcium chloride. Add sufficient calcium chloride so that it no longer clumps to pellets added earlier on the bottom of the flask. Remove the solvent using a rotary evaporator and weigh