Transcript of "4. elements, compounds, mixtures and colloids"
Technological Institute of the Philippines
938 Aurora Blvd., Quezon City
Experiment no. 4
Elements, Compounds, Mixtures and Colloids
Group No.2 of Section ES11FB4
Davis Banoog 1:30 4:30
Jenny-Ann Cabrera 1:30 4:30
Luis Miguel Benitez 1:30 4:30
July 19, 2013
July 27, 2013
Engr. Renato Agustin
1.1To identify and differentiate the fundamental characteristics of pure substances, mixture
APPARATUS AND MATERIALS:
Matter is composed of atoms that exist as solid, liquid or gas. It is classified into two,
pure substance whose molecules are made up of one kind of atom while compounds are
substances whose molecules are made up of two or more kinds of atoms combined in a
An element cannot e transformed into simpler substances, while compound may be
resolved into its elements; mixtures can be homogenous or heterogeneous. Homogenous
mixture has no distinguishing characteristics when seen by the naked eye. For
heterogeneous mixture, the substance still carries their identity when they are mixed and
displays more than one phase marked off by visible boundaries.
Colloid is a heterogeneous mixture of two or more substances in which their finely
subdivision molecules remain suspended in the dispersion medium for a considerable
length of time. Colloid possesses Tyndall Effect which is a property to scatter light in all
1 10 ml Graduated Cylinder
4 Test Tube
1 Test tube Rack
1 Test tube Holder
1 Test tube Brush
1 Triple Beam Balance
2 Watch Glass
1 25 ml Beaker
1 50 ml Beaker
1 Stirring Rod
1.1 Place 0.5 grams of sulfur in a watch glass. Observe its color, odor and state.
1.2 Get a bar magnet and draw it near the sulfur. Record your observation.
1.3 Place a pinch of sulfur in a test tube and add 5 ml of water. Shake it thoroughly.
Does the sulfur dissolved in water? Is it completely soluble, partially soluble or
1.4 Place 0.5 grams of iron fillings on a watch glass. Observe its color, odor and
1.5 Get a bar magnet and draw it near the iron filings. Record your observation
1.6 Place 0.5 grams iron filings in a test tube and add 5 ml of water. Shake it
thoroughly. Does the iron filings dissolved in water?
1.7 Mix thoroughly the sulfur and iron filings in a watch glass. Can you identify iron
and sulfur separately?
1.8 Run a magnet through the mixture. What did you observe?
2.1 Weigh 0.5 grams of NaCl crystals. Observe its color, odor and state. Test the
magnetic property of NaCl crystals. Record your observation.
2.2 Measure 5 ml of water in graduate cylinder and place in a test tube. Dissolve the
0.5 grams of NaCl in the water. Can you distinguish the NaCl crystals in the
mixture? What do you call the mixture?
2.3 Measure 5 ml of cooking oil. Observe its color, odor and state. Test the magnetic
property of cooking oil. Record your observation. Place 5 ml of water in another
test tube and add the 5ml of cooking oil.
2.4 Shake gently. Can you distinguish the cooking oil from the water in the mixture?
Record your observation.
3. Colloid (Tyndall Effect)
3.1 Place a beaker containing water against a beam of light.
3.2 Observe by viewing the beaker at the right angle to the beam of light. Is the light
scattered or did it pass through water?
3.3 Repeat by using 2% starch, soap and sugar solution. Record your observations?
Any substance that contains only one kind of an atom is known as
an element. Because atoms cannot be created or destroyed in a chemical reaction,
elements such as sulfur (S8) cannot be broken down into simpler substances by
It is consists of atoms of two or more different elements bound together.
Compounds can be broken down into a simpler type of matter (elements) by
chemical means (but not by physical means) and always contains the same ratio of
its component atoms.
A mixture is made from molecules of elements and compounds that are
simply mixed together, without chemical bonds. Mixtures can be separated using
techniques such as filtration, evaporation and distillation.
DATA AND RESULTS:
COLOR ODOR MAGNETIC
Sulfur solid yellow
unpleasant not attracted insoluble
S + Fe
not mixedIron Filings solid black odorless attracted insoluble
NaCl Crystal solid white odorless not attracted slightly soluble NaCl + water
Cooking Oil liquid yellowish unpleasant not attracted insoluble Cooking oil + water
(Element, Compound, Colloid, Solution)
Iron Filings Element
Sulfur + Iron Filings Compound
NaCl + water Solution
Cooking oil Colloid
Cooking oil + water Solution
Starch Solution Colloid
Soap Solution Colloid
Sugar Solution Colloid
MIXTURE OBSERVATION (Tyndall Effect)
Water the light passed through
Starch Solution light scattered
Soap Solution the light passed through
Sugar Solution light scattered
QUESTION AND ANSWER:
1. Did the addition of sulfur with iron filings produce a new compound? Why?
The difference between mixtures and compounds is that mixtures can be
separated again by physical means. Compounds must be separated by chemical
means. This is an indication that the atoms in a mixture are not holding onto each
other, they just happen to be nearby. In a compound, the atoms of the constituent
substances are connected atom-to-atom by chemical bonds. Chemical bonds are
where the atoms either share electrons between them (valence bonds), or exchange
electrons, and are then attracted to each other by electrostatic forces (ionic bonds).
You can mix iron powder and sulfur together, and separate it out again by using a
2. How did the mixture of sulfur and iron filings respond to the magnet?
The iron filings are attracted by the magnet because of its property making
the particles of iron filings separated from the sulfur.
3. How many phases do you observe when you add NaCl crystal in water?
We observed that when we add NaCl crystals in the water it has 2 phases:
soluble and the non soluble.
4. What is Tyndall Effect?
The Tyndall effect is the scattering of light as a light beam passes through a
colloid. The individual suspension particles scatter and reflect light, making the beam
visible. The amount of scattering depends on the frequency of the light
and density of the particles.