It was made of pure copper and was heavy! Another interesting fact about the first pennies was that they were designed and minted by a variety of private mints. This resulted in the variations of their design, weight and diameter. In 1792, the US Congress created the US Mint and the US finally had uniform currency. The first penny created by the US Mint was still made of 100% copper, over an inch in diameter, and its design had an image of a woman with long, flowing hair - Lady Liberty.
Pre Lab Objective: The purpose of this lab is to obtain the mass and volume of two different metal samples, to graph data, to obtain the slope of graphed data and to display a best fit curve of experimental data in order to graphically determine the density of each metal Background: Understanding the relationship that exists between a substance’s mass and its volume. This relationship is expressed by the physical property called density. (D = M/V). In order to determine the volume of solids, a technique called water displacement is used. A fixed amount of water is added to a graduated cylinder and the volume of water is recorded.
Tin's actual atomic radius is 140 pm. Use the math equation below to determine the percent error of your estimated value. Percent error = fraction: | actual value minus experimental (estimated value | over actual value × 100 This equation means that you subtract to find the difference between the actual value (given in this problem) and the experimental value (estimated from the graph). The numerator is in an absolute value sign, so the difference should always be positive. Take that difference and divide by the actual value (given in this problem) of tinâ€™s atomic radius.
Using the same electronic balance, the average mass of five copper slugs, in grams, will be determined. Lastly, by using the electronic balance again, the weight of two different unknown weights, in grams, will be determined by the weighing by difference method. Using both the direct weight and weighing by difference techniques, the weight of the copper slug (2.98 g) and the two unknown weights can be fairly accurately determined using the centigram balance. However, since the electronic balance can determine mass out to three decimal places, the electronic balance was more accurate weighing the copper slug (3.022 g) than the centigram balance using the direct weight and weighing by difference methods. Determining the mass of the two unknown weights (unknown weight #1 and #2) was determined using only the centigram balance using the weighing by difference method.
In order to find the equivalent weight a titration of the unknown acid had to be conducted. Equivalent weight is the weight of the substance in grams divided by the average molarity of the sodium hydroxide solution times the volume from the titration in liters. If the molarity of your sodium hydroxide solution were too low then the equivalent weight would be off significantly. In order to calculate a decent molarity a short series of titrating was conducted using KHP. Find the molarity is essential to numerous amounts of future procedures such as equivalent weigh.
Not only will we determine which one is the most resourceful for creating these packs, but we will also consider how much it will cost to actually produce them for the Dystan Medical Supply Company. In order to do this, we must find a way to determine the mass of each individual necessary in the production of a 100-mL cold pack that can attain a temperature of 0C and a 100-mL hot pack that can reach a temperature of 65C. To carry out our experiment, we will construct a calorimeter and record numerous thermograms using the MeasureNet station. In return, we will be able to tell from our
The change in enthalpy relies on the concentration of the salt solution, because different concentrations will produce different enthalpies. There is an equation to determine how much of this heat energy is lost or gained when a reaction is performed. Q = c m (T1-T2) Where: q is the energy in Joules C is the heat capacity, measured in joules per gram per degree Celsius M is the mass of the solution, measured in grams J is the joules G is the grams of water T is the temperature ΔH=ΔE + PΔV = (q p +w) – w = q p Procedure: 1. Follow instructions 1-9 in Appendix A-1 to initialize the MeasureNet workstation. a.
The (C1)(V1)=(C2)(V2) formula was used to determine how much to dilute the 0.1 g/L stock starch solution. These values produced a standard curve between concentration and their observed absorbance levels in the spectrophotometer. (0.1g/L)(x)=(0g/L)(4mL) X=0mL stock starch *(blank control) 4mL H20 1mL Lugol’s reagent *(must be added for spectrophotometer to read absorbency, not counted in final volume) (0.1g/L)(x)=(0.025g/L)(4mL) X=1mL stock starch 3mL H2O 1mL Lugol’s reagent (0.1g/L)(x)=(0.050g/L)(4mL) X=2mL stock starch 2mL H2O 1mL Lugol’s reagent (0.1g/L)(x)=(0.075g/L)(4mL) X=3mL stock starch 1mL H2O 1mL Lugol’s reagent (0.1g/L)(x)=(0.10g/L)(4mL) X=4mL stock starch 0mL H2O 1mL Lugol’s reagent After creating the known solutions from the concentrations found, the spectrophotometer was zeroed out (see TA for specific instructions on zeroing out spectrophotometer). Each known sample was then placed within the spectrophotometer and the corresponding absorbance levels were recorded and graphed, making a standard curve (see attached graph “Concentration vs. Absorbance”). For each unknown solution, 4mL of each solution was mixed with 1mL of
Part B: The graduated pipet’s average density at 22.3 °C was determined to be 0.9785g/mL with a percentage error of 1.89% shows the graduated pipet to be more accurate and precise. Part C: Density of an unknown NaCl solution was measured and a calibration curve used to determine the percentage of NaCl by mass in the solution. y=0.007x + 0.998 which concluded that the concentration of the sodium chloride solution was 3.14%. INTRODUCTION Anything that you can see, touch, taste or smell, occupies space and has mass, it is called matter. Matter can be a gas, a liquid,
Melissa Ramsahai Lab #10: Density and Buoyancy Lab Partner: John Adams Theory overview When calculating the area, A, of a block that has a width, w, height, h, and length, L, we use the following equation, A=L*w. With that same block, if we were to calculate the volume, we use the equation, A=Ah=L*w*h. IF we want to take the next step and calculate the block’s density, ρ, we would use the following equation, ρ=mv. Where m, is the mass of the block in grams. Water has a density of 1 gram per centimeter cubed or 1000 kilograms per meter cubed. Any object with and density that is less then that of water will float. When looking a beaker of water of depth, x, the water has a weight of F=mg and a pressure calculated using Forcearea.