Laboratory Techniques Essay

Let the water boil for about 5 minutes.

Record the temperature in Data Table 2. 3. Cold Water Measurements 1. Allow the 100 ml beaker to cool. Then fill the beaker with cold tap water and record the water temperature in Data Table 2. 2. Prepare an ice water bath by adding ice to the beaker filled with cold tap water. It may be necessary to pour out some of the water to make room for the ice.

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3. Immerse the thermometer in the ice bath and stir gently. Record the temperature in Data Table 2. 4.

Let the ice water stand for about 5 minutes. Then record the temperature in Data Table 2.To get an accurate measurement, ice should still be present in the water. Data Table 2 – Warm Water Measurements & Cold Water Measurement Hot water From -rap ( ‘C) Billing water (C)Billing water -5 Mint ‘C) ICC CO’S CO’S cold water From -rap ( ‘C water Ice water -5 Mint ICC CA 4. Volume Measurements . Fill a small test tube with water. Pour the water from the test tube into the 25 ml graduated cylinder. Record the 2.

Volume of a thin-stemmed pipette: 4. Completely fill a clean, empty pipette with water. 5. Hold the pipette vertically and add the water drop-by-drop too graduated cylinder until the water reaches the 1 ml mark. .

Count the number of drops in 1 ml. Record the data in Data Table 3 Data Table 3 – Volume Measurements Test Tube Volume (ml) Number of Drops in 1 ml Pipette Volume (ml) 10 ml 25 drops/ ml 4. 5 ml 5. Mass Measurements 1. Choose seven objects to measure. Remember, the scale can weigh a maximum mass of 500 grams or 18 ounces.

2. Record the hypothesized mass of the first object in Data Table 4. 3. Use the scale to measure the mass of the first object.

Record the measurement in Data Table 4. Then compare the hypothesis to the actual mass. 4. Repeat the previous steps for each of the remaining objects.

Data Table 4 – Mass Measurements Object Estimated Mass (g) Actual Mass (g) 1. Life Saver 2. 1 g 2.

4 g AAA Battery 8. 5 g 24. 4 g Golf Tee 0. 6 g 0.

9 g 3. 4. Key 4. 3 g 9. 9 g Paper Clip 1. 0 g 1.

G 5. 6. Penny 1. 4 g 2. 5 g push Tack I.

Go o. G 7. 1. Calculate the density of water.

A) Weigh a dry 25 ml graduated cylinder on the digital scale. Record the mass in Data Table 5. B) Pour 5 ml of water into the graduated cylinder.

Weigh and record the mass of the cylinder and water. ) Subtract the mass of the empty graduated cylinder from the mass of the graduated cylinder filled with water.The result is the net mass of the water. D) Calculate the density of the water using the formula d= 2. Calculate the density of spoilsport alcohol. A) Pour 5 ml of spoilsport alcohol into the graduated cylinder. Weigh and record the mass of the cylinder and alcohol.

B) Calculate the alcohol’s density using the formula d= MN. 3. Calculate the density of a saturated salt solution. A) Use the digital scale to weigh out 5 Goff Nasal, table salt. B) Pour the Nasal into the 100 ml beaker and add 12 ml of warm water. Stir the water/salt mixture then let any undisclosed salt settle to the bottom of the beaker.The liquid is now a saturated solution. C) Use an empty pipette to draw up only the saturated solution.

Be careful not to draw up any of the solid Nasal crystals. D) Measure 5 ml of the saturated solution into an empty graduated cylinder e) Draw up two consecutive pipits of saturated solution to reach 5 ml if necessary. F) Weigh and record the mass of the graduated cylinder and the saturated salt solution.

Determine the net mass of the salt solution. G) Develop a hypothesis as to whether the density of the salt solution should be rater or less then the density of pure water. H) *** Record the hypothesis in the Lab Report.I was able to follow the procedures in which stated specific steps in how to use these supplies properly, as I was knowledgeable of their use, especially first time use of the pipette. I feel that I have gained skill in using measuring devices such as the glass thermometer, digital scale and how to read a graduated cylinder, and other objects used in the lab.

I was impressed to see how fast the glass thermometer would rise and fall according to the temperature of the water in our experiment. I also liked how this lab put in perspective how you need accuracy when it comes to agreements.Especially when having to pour the liquids from the beaker to the graduated cylinder, or the small pipette. Inaccuracy will set off the whole conclusion you are trying to find. When I determine the objects density, I found it very fascinating when using different substances.

First of my surprises was that the alcohol was less dense than water and of less mass. When Just looking at the two, you would think they would be the same. However when adding in the salt, it was easy then to figure out that the salt would be of higher density due to adding in the element mixture.Also first measuring different object in the beginning of the lab, gave the idea of their mass of objects. Then later in the lab measuring volumes, and densities how relatable they are all to one another.

Without one and understanding the concept, you are not able to figure out the other answers. My favorite finding of the lab was at the end when using the two different methods to find the densities of the objects. Table 6, Water Displacement and Archimedes Method, both found the exact same answers. It was neat to see totally two different methods obviously find the same conclusion.

The Archimedes method was totally new to me.


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