Characteristics of Matter (chem 14.1)

Experiment # 1: Characteristics of Matter                                                                       March 17, 2016

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1. Abstract

        This experiment deals with the characteristics of matter. It is divided into three major parts.  In Part A, different physical separation methods of components of a mixture were identified. In Part B, classification of metals or non-metals was known through identifying different properties of matter. On the other hand, the differences between physical and chemical changes were observed in Part C.

II. Keywords

        physical separation, metallic properties, nonmetallic properties, acid and base, chemical reaction, physical and chemical changes

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III. Introduction

        Matter is defined as anything that occupies space and has mass. It is said to exist in four states namely, solid, liquid, gas and plasma. Matter can be classified as pure substance or a mixture depending on its composition. Anything that has a definite composition like elements and compounds are said to be pure substances. On the other hand, anything that is composed of more than one substance are said to be mixtures. These may be further classified into solution, colloids, and suspensions based on the particle size (Helmenstine, 2015).

In nature, majority of the substances are mixtures. As mentioned, it is made up of two or more pure substances physically combined. Thus, components of mixtures can also be recovered or be separated through physically means. There are several ways to separate substances, depending upon the nature of the components of the mixture. Filtration is a physical process use to separate suspended solid matter from a liquid, by causing the latter to pass through the pores of some substance, called a filter. Evaporation is also use to separate components of solution wherein the liquid is heated to the point of vaporization, leaving solids behind. Other physical means of separating are adsorption, chromatography, sublimation, magnetic separation, solvent extraction and many more (eschooltoday, 2016).

Components of mixtures can also be classified according to its properties. They may be classified into metals or nonmetals. Moreover, these components of mixture may undergo physical and chemical changes. The most common types of chemical changes are combination (two or more reactants form one product), decomposition (a compound is broken down into elements or simpler compounds), single displacement (a more active element replaces out another less active element from a compound), double displacement (two species are displaced), combustion (a compound combines with the oxygen gas in the air) and redox (reactions in which electrons are exchanged) (Crawford, 2016).

        A deeper understanding about these will is gained through this experiment which aimed to identify the different methods of separating components of a mixture, applying the laboratory techniques needed for each method of separation, differentiating metals from non-metals, physical from chemical change, and determining the relative reactivities of different elements.

IV. Experimental

The first part of the experiment notes the conditions, methods and applications of the different separation techniques. The separation techniques employed are filtration, sublimation, adsorption and solvent extraction.

A weight of 0.2 grams each of iron (Fe) filings, ground mothballs and table salt were weighed and mixed in an evaporating dish, 2 strips of Magnesium ribbon and a pinch of food coloring were added. The mixture was scattered thinly on a piece of paper and then a magnet was passed underneath the paper. The component separated by the magnet and the rest of the mixture were saved for the next experiments.

The remaining mixture was placed in a 50 mL beaker and 30 mL of water was added, stirred for a minute using a glass rod, and then filtered. The filtrate was saved and the residue was transferred to an evaporating dish. A piece of perforated filter paper was placed on top of the evaporating dish containing the residue and an inverted funnel with a cotton plug on its tip was placed on top of the perforated filter paper. The evaporating dish was heated until solids were deposited on the walls of the funnel. The deposit on the funnel and the residue on the evaporating dish were saved for the next experiments. The residue on the evaporating dish is to be identified.

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Figure 1: Setup for the residue with the use of the funnel, and perforated filter paper

The filtrate is boiled and a pinch of activated charcoal was added, boiling was continued until the mixture was about 20 mL. The mixture was filtered and the filtrate is saved in a test tube. The filtered mixture was observed to identify the substance that was separated.

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Figure 2: Setup for the filtrate with activated charcoal

The 2mL filtrate was added a crystal of Iodine, shook (again the filtrate was saved for the next experiment), about 1 mL of hexane was added and was observed to identify the color of the hexane and aqueous layer. The two layers were separated by means of medicine dropper, and observed to identify the method of separation and properties of the components of the mixture. The layers were evaporated and the residues were observed, both hexane and aqueous layer respectively.

The second part of the experiment dealt with the analysis of the mixtures that classified them as metals or non-metals.

Small amounts of the substances Fe, Mg, I2 and mothballs that were isolated in the first part of the experiment were put in separate test tubes, added with 10 drops of 0.1 M hydrochloric acid, covered immediately with a stopper afterwards, and observed for continuous evolution of gas. The gas was observed, tested with a glowing splinter and identified which was metallic and non-metallic.

A piece of magnesium ribbon was heated until burned and turned to ash then placed in a test tube with 5 mL water and shook the test tube. The solution was tested with litmus paper to identify whether it was acidic or basic.

(Performed in the hood) The tip of the glass rod was heated in blue flame for a minute and then dipped in powdered sulfur placed on a watch glass. Again, the tip of the glass rod with powdered sulfur is heated over a blue flame; the fumes were collected in a test tube stoppered by a cork. 1 mL of water was added, shook the test tube and tested the basicity or acidity of the solution.