Scientific Measurements, Precision, and Accuracy of Laboratory Glassware When conducting experiments, scientists must understand the significance of accurate and precise measurements while utilizing the correct volumetric containers that are used to quantify data. That way, all information that is collected can be trusted and accurately reflects the facts of the investigation. When measuring the volume of aqueous solutions, it is imperative to acknowledge the accuracy, precision, and percent error of the measurements. Accuracy is how close the results are to the actual accepted measurement, also known as the “true” value. Precision is how close two or more measurements are relative to each other, only found by measuring a solution multiple times. Percent error is the difference between an an accepted value and a measured value, and is used to determine the accuracy of measurements.Understanding the importance of the aforementioned terms will lead to more valid experiments.
State Problem/ Purpose:
The purpose of this experiment is to learn the differences between the accuracy/ precision of three pieces of laboratory glassware, as well as to understand when to make an approximated measurement or an exact one. Using a volumetric pipet, graduated cylinder, and a beaker will yield different accuracies, due to the nature of the glassware. Thus, as mentioned before, it is important to understand when to know that one’s data is reliable or not. The formula “density = mass/volume”
15. Which parameter of glass is measured with bromoform and bromobenzene mixtures in a column?
In this lab experiment our main focus was to get skillful in using tools such as the metric ruler, balances, thermometer, and graduated cylinder to capture measurements of length, mass, temperature and volume. Additionally, this lab helped us to become more familiar with the uncertainty of measurements, as well as becoming efficient with rounding our measurements to the correct numbers of significant figures. Our results are measured consistently with rounding to the closest answer we could possibly acquire as the data can tell you.
There are several sources of error to this experiment due to random and systematic errors. The only source of random error was the measurement that we took through the graduated cylinder which was only accurate to the nearest 1%. We took the largest error from this one percent, which was +/- 3. The largest relative error this yielded was only 3%, so this did not affect how precise this experiment was too much. We can still make this more precise by making the masses of the water larger. For example if we started the masses at 300mL and went up by 50mL, the largest error this would yield would be 2% due to the largest error being +/- 5. This would cause smaller errors in the amount of water.
because each of the objects displaced the water by 1 mL, their mass over that mL is their density.
CHM130 Lab 6 Exploring Density Name A. Data Tables Place your completed Data Tables here Part IIIa (3 points) Volume of water in graduated cylinder (mL)10 mlMass of rubber stopper (g)11.15Volume of water and rubber stopper (mL)16.5 Part IIIb (6 points) Volume of water in graduated cylinder (mL)20Mass of iron nail (g)3.66Volume of water and iron nail (mL)20.5 Part IV (20 points) Type of Aluminum FoilMass (g)Length (cm)Width (cm)Volume (cm3)Thickness (cm)Regular.63g15 cm 10.02 cm.21 cm3.0014 cm Heavy Duty.97g15 cm10.01 cm .36 cm3.0024 cm B. Follow Up Questions Show all work for questions involving calculations. Part I Use the concepts/vocabulary of density to explain why the liquids formed layers in Part I of the procedure. (8 pts)
3. Analyze: What do you notice about the density of the Styrofoam pieces? The density remains the same.
Procedure: Using distilled water, premeasured containers and objects determine displacement of fluids and density of objects. Use ice and heat measure temperatures in Celsius, Fahrenheit and Kelvin.
In Special Glasses, Billy Collins utilizes humor and a lighthearted tone to create a much darker theme involving death and loss.
Procedure: I used a ruler, thermometer, and scale to take measurements. I used a graduated cylinder, short step pipet, scale, and ruler to determine volume and density. I used a volumetric flask, graduated pipet, pipet bulb, scale, and glass beaker to determine concentrations and densities of various dilutions.
Abstract: The objective of the lab is to determine the volumes of the polystyrene spheres with three different measuring tools: Water Displacement, Analytical Scale, and Triple Beam Balance Scale. The experiment is meant to help understand the concept and application of precision and accuracy in experimental measurements. Accuracy is a measure of how closely the results of repeated measurements are to the true value of what is being measured. Precision is the variability in the results from the repeated measurements, and how close the repeated measurements were to one another. In this lab, the method for measuring the volume of the polystyrene spheres is done with the previously stated tools: Water Displacement, Analytical Scale, and Triple Beam Balance Scale. The standard deviation for the entire classes volumes and masses are recorded to determine the densities.
2. In order to calculate the density of a solid or liquid sample, what measurements are needed?
When all the knowledge in the world fails to bring you happiness in life, where do you turn? In the case of the Glass Siblings, the answer to this question is spiritual enlightenment. Specifically, they are interested in Eastern religious philosophies. References to these philosophies – such as Taoism, Buddhism, and Hinduism – are found throughout the Glass novellas. The beliefs of the various members of the Glass family are frequently revealed through the children they encounter or observe. Throughout the Glass stories, small children are portrayed as spiritually advanced, with much to teach adults.
In the third stage of this experiment, the density of a liquid was determined and compared to known standards. A 100ml beaker was filled to about half-full with room-temperature distilled water. The temperature of the water in ◦C was recorded in order to compare to known standards later. A 50ml beaker was then weighed on a scale in order to determine mass and recorded. A sample of the distilled water with an exact volume of 10ml was then placed in the 50ml beaker using a volumetric pipette. The 50ml beaker with the 10ml of water was then weighed again and the initial mass of the beaker was subtracted from this mass to obtain the mass of the 10ml of water. With the volume and the mass of the water now known, density was calculated using d = m/V and recorded in g/ml. This process was then repeated to check for precision and compared to standard values to check for accuracy. Standard values were obtained from CRC Handbook, 88th Ed.
SU-8 Photoresist Patterning on a 3” Glass Wafer (Ti coated) to fabricate microstructure test pattern.
In this experiment, The purpose of this experiment is to investigate the measurement of the actual volume contents of volumetric glassware. In the beginning of the experiment, the volumetric glassware should be clean and dry before used. The volumetric glassware, measuring cylinder and pipette should be handled with care and all the precautions were be taken during the experiment was held. This was to ensure to avoid any errors such as parallax error especially while reading water meniscus. This experiment must be repeated three times or more and take the average reading to get more