Unknown Mixtures Lab Report

We were assigned mystery powder convertible which contained calcium carbonate, baking soda, and sucrose. We found out that the mystery powder had calcium carbonate because when it reacted with iodine it turned orange/brown. When calcium carbonate reacted with vinegar it had a fizzy-like reaction. It also reacted with hydrochloric acid and that caused it to bubble. When we tested the mystery powder it also turned orange/brown when we added iodine. Also when we added vinegar and it also fizzed like the calcium carbonate. Again when we added the hydrochloric acid it reacted exactly like calcium carbonate, lots of bubbles were made. We know that the calcium carbonate was in the mystery powder because it had similar reactions.

This experiment combined all the knowledge of the previous labs performed throughout the semester. An unknown mixture containing an organic acid or base and an organic neutral compound in nearly equal amounts needs to be separated to its separate components. An understanding of solubility, extraction, crystallization and vacuum filtration is necessary in order to

Abstract: One mixture of two unknown liquid compounds and one mixture of two unknown solid compounds were separated, isolated, purified, and characterized by boiling point. Two liquid unknowns were separated, isolated, and purified via simple distillation. Then, the process of an acid-base extraction and washing were used to separate two unknown compounds into two crude compounds: an organic acid and a neutral organic compound. Each crude compound was purified by recrystallization, resulting in a carboxylic acid (RCO2H) and a pure organic compound (RZ). The resulting mass of the pure carboxylic acid was 1.688g with a percent recovery of 31.80%, the boiling range was 244-245 °C, and its density was 2.0879g/mL. The resulting mass of the pure organic solid was 2.4902g with a percent recovery of 46.91%, the boiling range was 52.0-53.4°C, and its density was 1.5956 g/mL.

In 2 and 7 I added 50 mL of .1 M NaCl. I added sodium acetate to the rest of the beakers: 1 gram to 3 and 8, 5 grams to 4 and 9, and 10 grams to 5 and 10. I then filled the beakers that contained the solid sodium acetate with 50 ml of .10 M acetic acid. Specifics can be found on page 84 of the lab manual. Though the lab manual instructed to use a pipet, we did not have an accurate 1 mL pipet or a graduated pipet, so we instead prepared two graduated burets with 1 M Sodium Hydroxide and 1 M hydrochloric acid. Using a standardized pH probe with a Lab Pro to measure changes in pH, we added 1 mL of HCl at a time and recorded the changes. The same was done for the NaOH.

4. The melting points of the solids were tested by placing them in crucibles and heating them using a hot plate.

Three grams of a mixture containing Benzoic Acid and Naphthalene was obtained and placed in 100 ml beaker and added 30 ml of ethyl acetate for dissolving the mixture. A small amount (1-2 drops) of this mixture was separated into a test tube. This test tube was covered and labelled as “M” (mixture). This was set to the side and used the following week for the second part of lab. The content in the beaker was then transferred into separatory funnel. 10 ml of 1 M NaOH added to the content and placed the stopper in the funnel. In the hood separatory funnel was gently shaken for approximately one minute and vent the air out for five seconds. We repeated the same process in the same manner one more time by adding 10ml of 1M NaOH.

The purpose of this experiment was to classify unknown solids based on their type of chemical bonds by investigating their properties. By using data, Unknown 1 was classified as a metallic. This was because it appeared a shiny copper color, had a very high conductivity as a solid, had a high melting point, and was malleable. Unknown 2 was classified as a nonpolar covalent bond. This was because it had no conductivity as a solid and low conductivity in water.

Objective: The objective of this experiment is to use acid-base extraction techniques to separate a mixture of organic compounds based on acidity and/or basicity. After the three compounds are separated we will recover them into their salt forms and then purify them by recrystallization and identify them by their melting points.

ii. The second part of the titration series involves titration of NaOH with Hydrochloric acid (HCL). Again, three reps of titration and a blank titration have to be completed. A volumetric pipet is used to measure 10.00mL of HCL into three labeled conical flasks. Then the flasks are filled with deionized water until about the 50mL mark. A buret is

After dissolving benzoic acid in 1.0mL CH2Cl2 and 1.0mL 10% NaHCO3 solution, two layers are created, the top layer is 10% NaHCO3 solution and the bottom is CH2Cl2.

Aim: To classify unknown substances according to their structure type and to observe how the structure of materials affects their uses.

The guiding question of this ADI lab was, “What are the identities of the unknown compounds?” The goal of this lab was to understand the relationships between moles and molar mass to find the identity of unknown compounds. The mole can be used to measure small amounts of a substance or is used to convert from unit to unit using dimensional analysis. One mole is equivalent to the molar mass in grams of that substance. If you start with the moles of an unknown substance, multiply it by a given compound’s molar mass, and then divide it by however many moles are in the compound of your choice, you will get the mass of the compound. With that answer you can then compare with mass of the compound in the bag to determine its identity. We first started

As the acid was being added, the mixture was being stirred over a stir plate. Once completed, the reaction mixture was poured from the round bottom flask into a 500 mL separatory funnel and its top (organic) layer was extracted into another beaker. The bottom (aqueous) layer was placed back into the funnel and extracted twice with 50.0 mL of ethyl ether each. The newly extracted layers were combined and dried over magnesium sulfate (MgSO4). The dried solution was the decanted into a beaker to remove the MgSO4 salts and the product solution was collected via Buchner vacuum filtration. The resulting product was transferred into an Erlenmeyer flask with an inverted beaker on top and stored in a drawer.

In the lab “Mixed Substances,” the objective was to see how properties of individual substances compare with properties of a mixed substance. The word mixture can be defined as a combination of two or more substances that are mixed together physically, not chemically. A homogeneous mixture is a mixture in uniform structure or comparison throughout the substance (Ex. Milk/ Popsicle). Lastly, a heterogenous mixture consists of dissimilar parts and elements (Ex. Pizza/ Salad).

Identifying Substances Using Properties Purpose: To identify unknown substances by observing their physical and chemical properties (e.g. colour, state, clarity, crystal shape, behaviour in water, behaviour in acid), and comparing them to the physical and chemical properties of known substances. Hypothesis: I predict that by observing and testing the properties, as well as comparing them to those of known substances, we can identify all 5 of the unknown substances.