Idenitfication of Substances by Physcial Properties

I. LIQUID - Identification of an Unknown Liquid: Using the physical properties of Solubility, Density, and Boiling Point.

3. Turned off the laboratory burner and observed the properties of the product in the evaporating dish.

The purpose of this lab was to determine the limiting reactant in a mixture of to soluble salts and the percent composition of each substance in a salt mixture.

Purpose: The purpose of this experiment is to observe chemical changes in common consumer products to determine if the chemicals are basic, acidic, or remain neutral when mixed with other chemicals.

The purpose of this lab is to study some of the physical properties of two types of solids – ionic and molecular. The samples used are sodium chloride (ionic) and camphor (molecular). The physical properties studied are odour, hardness, melting point, solubility in water and solubility in 2-propanol. It is observed that some of the physical properties of sodium chloride are no odours, hard, a high melting point, soluble in water and insoluble in 2-propanol; some of the physical properties of camphor are a strong odour, soft, a low melting point, insoluble in water and soluble in 2-propanol. A few conclusions can be drawn from these

The purpose of this lab is to test substances and to determine the physical and chemical properties of substances.

The objective of the experiment was to observe different reactions with different chemicals. The experiments emphasized on the chemical changes occurring in acids and bases as well as color changes and bubble formations. The experiments allowed for a better understanding of the undergoing chemical changes in mixtures. Some mixtures instantly changed colors while others were transparent or foggy. Some mixtures produced thick color that created solids called precipitates. Mixtures KI + Pb(NO3)2 and NaOH + AgNO3 both produce noticeable precipitates after a while. It was interesting to see the different acidic and base reactions like the fuchsia color formation in NaOH + phenolphthalein.

The purpose of this lab is to separate a mixture and determine the percentages of each of the ingredients. Each substance will have a different boiling point due to its intrinsic properties and from that, we will be able to determine the purity of different products as we evaporate off the next level of product.

Most notably the reaction with heat and hot and cold liquid were interesting. Several attempts were made to obtain a smell from the reactions but none were found. When the samples were heated in water several of them had violent and/or sudden reactions.

The purpose of this lab is to become more familiar with the products of different types of chemical reactions by conducting several chemical reactions and observing the changes that occurred. In addition, by performing various experiments, the observations will help in writing chemical equations, which represent the process involved in a chemical reaction. Overall, the chemical changes observed throughout can determine the products that are formed from the reactants. In chemical reactions, substances that are referred to as reactants produce other substances called products. There are several ways to determine that a chemical reaction has occurred, and which type of reaction has taken place, exothermic or endothermic, which will help predict

By determining and examining the average density and the average boiling point of the unknown liquid, it appears that the unknown liquid is methanol. The average boiling point of the unknown liquid is calculated to 69.8°C and its average boiling point is near the boiling point of ethanol, which is 64.7°C. While these values are not extremely close, we see further similarity regarding the densities. The average density of the unknown liquid is calculated to 0.7574 g/mL and the density of methanol is 0.791 g/mL. However, there were calculation errors while performing the experiment during trial 3 when using the volumetric pipette and during trial 1 when using the burette.

The purpose of this experiment is to identify an unknown substance by measuring the density and boiling point. I will be able to conclude which substance is my own from a list of known options stating what its real boiling point and density is.

An ice bath was prepared in a large beaker and a small cotton ball was obtained. 0.5 g of acetanilide, 0.9 g of NaBr, 3mL of ethanol and 2.5 mL acetic acid was measured and gathered into 50mL beakers. In a fume hood, the measured amounts of acetanilide, NaBr, ethanol and acetic acid were mixed in a 25mL Erlenmeyer flask with a stir bar. The flask was plugged with the cotton ball and placed in an ice bath on top of a stir plate. The stir feature was turned on a medium speed. 7mL of bleach was obtained and was slowly added to the stirring flask in the ice bath. Once all the bleach was added, stirring continued for another 2 minutes and then the flask was removed from the ice bath and left to warm up to room temperature. 0.8mL of saturated sodium thiosulfate solution and 0.5mL of NaOH solution were collected in small beakers. The two solutions were added to the flask at room temperature. The flask was gently stirred. Vacuum filtration was used to remove the crude product. The product was weighed and a melting point was taken. The crude product was placed into a clean 25mL Erlenmeyer flask. A large beaker with 50/50 ethanol/water

The purpose of this lab was to study colligative properties. These properties are properties that are affected when a solute is added to a solvent. Thus, the amount is important, not the actual type of substance, for the colligative properties. A couple types of this property are the freezing point and boiling point of a substance. (1)

The objectives of this lab are, as follows; to understand what occurs at the molecular level when a substance melts; to understand the primary purpose of melting point data; to demonstrate the technique for obtaining the melting point of an organic substance; and to explain the effect of impurities on the melting point of a substance. Through the experimentation of three substances, tetracosane, 1-tetradecanol and a mixture of the two, observations can be made in reference to melting point concerning polarity, molecular weight and purity of the substance. When comparing the two substances, it is evident that heavy molecule weight of tetracosane allowed