expt 1-characteristics of matter
DESCRIPTION
Chemistry 14.1 - General Chemistry Laboratory ITRANSCRIPT
Experiment 1: Characteristics of Matter
Apolega, Melissa Ann Kim
Dizon, Diane Marie
Group 1
Characteristics of Materials Used in the Experiment
Iron (Fe) filings Magnetic, malleable, with silver/grey coloring Most familiar element to display corrosion
Mothballs Non-polar organic solids Aromatic compound that sublimes easily
Table Salt (NaCl) A well-known ionic compound Brittle, and known to conduct electricity in the
molten state in an aquaeous solution
Magnesium (Mg) ribbon White ash=result of burning Mg ribbon Mg combines with oxygen to form magnesium oxide When water is added forms magnesium hydroxide, a
base Food Color
Substance added to change food/beverage color Also used for educational purposed and laboratories
Iodine (I2) crystals Lustrous, grey-black substance When heated gently, it vaporizes into a purple gas,
exhibiting sublimation
Hydrochloric Acid (HCl) Magnesium and iron corrode easily in acid
solutions such as this Dissolves metals to form oxidized metal chlorides
and hydrogen gas (formation of bubbles)
Ferric Chloride (FeCl3) Mild oxidizing agent that dissolves metals (ex.
Copper and iron) A moderately strong Lewis acid, highly corrosive
and toxic Sulfur (S) powder
If heated, forms sulfur dioxide
Hexane (C6H14) Alkane hydrocarbon, frequently used as inert
solvent in organic reactions due to its being non-polar
Does not dissolve in water
Methods of Physical Separation: As Applied in Ex. 1
Filtration Solid and liquid separated by a porous
medium (filter paper) Sublimation
Solid transformed into gaseous state without passing through the liquid phase (vaporization of iodine and naphthalene)
Solvent Extraction Method of separation where two immiscible
solvents form two layers in the solution, making it easy to pour each separately
Adsorption Means to adhere to a surface Occurs as atoms or ions at the surface of a
solid are extremely reactive
Chemical Properties of Metals Metals are lustrous in appearance. Most of them are solid at room temperature, good
conductors of heat and electricity exhibit malleability and ductility. generally have low electronegativities, having the
tendency to form cations and have positive oxidation numbers
The reaction of a metal with either an acid or metal salt is called a displacement reaction. This occurs because the ion in the solution is displaced or replaced through oxidation of an element..
Chemical Properties of Nonmetals
Nonmetallic elements are poor conductors of heat and electricity, unlike metals.
exhibit both positive and negative oxidation numbers.
more electronegative than metals; they can readily accept electrons when they are subjected to reactions.
Physical and Chemical Changes in Matter
In a physical change, no new substance is formed after the process but only phase changes occur; melting, freezing, vaporization and sublimation are some examples of a physical change.
At the occurrence of a chemical change, a new substance is formed. Indications that a chemical reaction has taken place include: emission of light or heat, change in color, gas production, odor, or sound.
Results and Discussion Reaction of Metallic and Non metallic
substances with HCl Iron evolution of gas (chemical) Magnesium evolution of gas (chemical) Mothballs no reaction Iodine no reaction
Evolution of gas is an indicator that a chemical reaction has occurred. As this had been observed in the experiment evidently in iron and magnesium as they reacted with HCl, the changes have been identified as chemical in nature
Classification
Iron metallic Magnesium metallic Mothballs nonmetallic Iodine nonmetallic
Reaction with FeCl3 Iron no change Magnesium showed chemical change
Reaction of Oxides with Water Magnesium Oxide almost not dissolved Sulfur Dioxide partly dissolved
Basic/Acidity Magnesium Oxide Basic Sulfur Dioxide Acid
Metal Oxides Most are ionic compounds Those that dissolve in water react to form
hydroxides and are called basic anhydrides or basic oxides
Nonmetal Oxides Oxyacids result from most nonmetal oxides
combining with water Oxides that react with water to form acids are
caled acidic anhydrides or acidic oxides
Chemical Properties of Metals and Nonmetals based on the Experiment Metals
Evolution of Gas upon reactionReactive with Acids
NonmetalsNo evolution of gas observed in substances
tested non-reactive with acids
Oxidation occurs as metals react with the acidic solutions. Acids are combinations of nonmetals combined with hydrogen and oxygen, thereby oxidizing metals which are known to lose electrons in reactions like these.
A Comparison between Iron and Magnesium
In the activity series, magnesium is located higher than iron; magnesium is more easily oxidized compared to iron and can therefore react more readily to form compounds. With this fact, it can be said that magnesium is more reactive than iron as it undergoes various reactions.
Changes of Matter upon heating and type Iron burns (P) Food Color burns (C) Iodine purple vapor formed (P) Naphthalene particles move away from
flame (P) NaCl burns (P) Mg Ribbon white ash formed (C)
Significant Observations Change in iodine crystals
When heated, crystals were directly changed into the gas state in the form of purple vapor (sublimation)
Formation of white ash on the mg ribbonEvidence of the formation of magnesium
oxide as fumes form. If combined with water, this forms magnesium hydroxide (basic)
Most substances heated underwent physical changes only as phase changes were observed in the experiment
Balanced Reactions
MgO (s) +H2O Mg (OH)2
SO2 (g) +H2O H2SO3
2Fe + 6 HCl 2FeCl3 +3H2
Mg + 2HCl MgCl2 + H2
3 Mg + 2FeCl3 3MgCl2 +2Fe
Conclusion
It can therefore be concluded that properties of matter are crucially considered when substances are subjected to reactions. As substances are subjected to reactions, their properties also manifest during the reaction
Sources
Chang, Raymond. Chemistry. International Edition (5th). McGraw-Hill, Inc., New Jersey, USA. 1994
Brown, Theodore, Lemay, H. Eugene, Bursten, Bruce and Burdge, Julia. Chemistry the Central Science. 9th Edition (Philippine ed). Pearson Education South Asia. 2004
en.wikipedia.org