Lab 1-3: Seperation of a mixture

In this lab "Separation of a mixture" you begin by mixing sand, salt, and iron filings with a total mass close to 50 grams. Next you need to make a procedure to separate the mixture with a purpose of "determining" the amounts of components withing the mixture. To separate the homogeneous mixture my group began to separate the iron using a magnet to pull the filings out of the mixture. After we measure its mass we then add water to the remaining mixture. We mixed the water thoroughly with the salt and sand so the salt would dissolve leaving only the sand to be filtered through. Using the filter paper we then separate the sand and measure its mass. Lastly we placed the beaker filled with the remaining mixture on a hotplate this caused the water to evaporate leaving only salt behind that you then scrape from the beaker to measure its mass.

1.Mass's required through this experiment may be different then beginning mass measured. This can be because during the separation some amounts of sand was picked up with the iron filings with the magnet or when straining the sand some salt was left behind this can change measurements. 
2.To make separations more accurate we could have done required processes twice, using the magnet and and filter the sand from saltwater a second time.
3.The final answers required was rounded to three digits, this is because the beginning mass we measured contained three digits.

In relation with class topics and discussions this lab help establish an understanding of homogeneous and heterogeneous mixtures. How the salt and water bonded and could only be separated by heat from the hot plate demonstrate a homogeneous mixture. The rest of the mixture that could be separated by a magnet or filter paper show a heterogeneous mixture and how the particles do not attract making it easier to separate them from the mixture.
 

Lab 1-2: Indirect Measurement

In this lab indirect measurement is used to find the diameters and thickness of aluminum foil and copper wire. To determine these values the volume is calculated after finding the mass and density of your object. Mass is found by weighing the copper wire and aluminum foil on a scale and then using its density located in Table S of the reference tables. With these two values i then can use the formula resulting in volume.The volume is crucial to finding the thickness or diameter with the help of length and width. When calculating the thickness of the regular aluminum foil the mass was weighed to about 1.46g this divided by aluminum's density of 2.98g/cm3 equals your volume.Using the resulting volume of .541cm3 you then measures the length and width and the plug the values into the formula V= L x W x Thickness. You then solve for T, the thickness comes out to be .0013cm. You repeat these sames steps for the heavy aluminum foil with different measurements the thickness resulted in .0023cm. The Copper wire uses the same steps for volume but substitutes different values for density and mass pertaining to the copper wire. After measuring the length the copper wires volume .035cm3 and length is then substituted in the formula for the volume of a cylinder. After you solve for "r" (radius) your must multiply this answer by two to get your diameter .064cm. Some methods of indirect measurement are better then others depending on your object. For example the thickness and diameter was to small to measure with a ruler or water displacement so you used indirect measurement of volume.

When calculating the actual thickness of the foil you may end up with a bunch of decimals, this may be a result that is good or bad. The decimals give you a more precise measurement of thickness but also with more numbers you have a higher chance of error. Some sources error may come from rounding values like length to the nearest tenth. A scale is also sometimes imprecise in its measurements and these calculations alter you volume and diameter. Indirect measurement is better for things not used industrially like buildings or bridges that call for exact measurements for stability in structure. Indirect measurement is for purposes when you don't need something precise. An example is if you want to store something in jars and you don't know the jars diameter indirect measurement can be used to find its measurement through volume of a cylinder formula.

Lab 1-1: Properties of Green Stuff

The procedure pertaining to this lab "Properties of Green Stuff" include two beakers, one filled with 25ml of water and the other to hold the copper (II) chloride. After recording your observations of the dry copper (II) chloride you pour your 25 ml of water into the beaker holding the "green stuff". After stirring the mixture completely make observations of the finished product. Next using the eye dropper place a few drops of this mixture onto the given aluminum foil. After observing the reaction tear the foil into pieces and place it into your mixture. When finished making observations you dispose of your mixture and properly put away you equipments used for the experiment.

Determining whether the properties of the "green stuff" is physical or chemical can be simply stated. A physical change changes the appearance of the substance which can commonly be observed through our senses. A chemical change changes the composition of the substance when it interacts with another substance. For example the copper (II) chloride before mixing it with water was brown, when it touched water the copper (II) chloride turned green ergo "green stuff" this is a physical change. When the "green stuff" was completely mixed with water the mixture caused a chemical reaction turning to copper when reaching the aluminum foil is a change in composition.

In the this lab the water was the liquid the copper (II) chloride was the solid and the reaction of the mixture on aluminum foil was the gas. Solids are compacted particles with little space between like the "green stuff" the liquid (water) has moving particles only confined by its container its kept in. The mixture of these cause an reaction on aluminum causing a gas to rise(spaced out bustling particles in a random state of motion). In class we are learning the different states, properties, and types of matter. This experiment demonstrates this through the different substances used through this lab and its changes. One question was why did the substance change green and the water is blue?