The Effect Of Beer Lambert 's Law And Spectrophotometry

Density is the amount of matter per unit of measurement (Merriam-Webster. Merriam-Webster, n.d. Web. 26 Aug. 2016.). If water has a density of 1.0 g/mL and you place a substance with a density of 1.8 g/mL the substance will sink because it is denser than water. Density is often measured in g/cm^3 or g/mL because the formula for density is D=m/v.

After the serial dilutions of the red and blue dyes were taken, the molarity and absorbance for both dyes were calculated. Using the MiVi = MfVf equation, the concentrations for each value of the red and blue dye were separately calculated. Calculating absorbances calls for setting the correct wavelengths of light for each dye. In this case, the 470 nm wavelength for red dye and the 635 nm wavelength for blue dye was needed to find the maximum absorbances. The absorbance was found by blanking the colorimeter and entering the concentrations. After both values of the absorbances and concentrations were found, the values were then graphed in order to obtain the equation of the relationship between absorbance and concentration.

Density was an important part of this lab. Density can be defined as the ratio of the mass of an object to the volume. To find the density of an object, simply divide mass and volume. The equation looks like this: D=M/V. Density is an intensive property that depends only on the composition of a substance, not the size of the sample.

From this graph and chart we can see that the higher the concentration the higher the absorbance, all the different concentrations were tested at the same wavelength (625nm). Also we can determine our unknown substances concentration by using the absorbance we got for it. The red dot on the graph followed by the line towards the horizontal axis indicates that the concentration of fast green was 34% or 5.1x10-3.

The ending result of this experiment confirms that as five test tubes are lined up with the varying level of absorbance, different results in the level of absorbance will appear as well, this is visible in above table. Thus, this is due to the varying amount of water in the solution. The blank sample had a 0.30 in its level of absorbance.

Time) because it had a correlation closest to 1. All three orders were graphed and a linear regression was used to see which graphed order was closest to 1. The order was determined by comparing the concentration and time to the mathematical predictions made using the integrated rate laws. Analyzing each graph and finding each correlation helped determine which graph was closest to 1. The more concentrated a solution is, the higher the absorbance of that solution. This is due to Beer’s Law. The law measures the absorbance of a solution by determining how much light passes through a solution. As the concentration of a solution increases, fewer wavelengths of light are able to pass through the concentrated solution. The absorbance at 60 seconds was 0.573 (Figure 1: Table1). To calculate the concentration (molarity), the Beer’s Law equation was used, Abs = slope(m)+b. Plugging in what is known into the Beer’s Law equation resulted in 0.573 = 3.172e+004 + 0, where the concentration is determined by M = 0.573-0/ 3.172e+004. So, the concentration at 60 seconds using the equation (M = 0.573-0 / 3.172e+004) was 1.824e-5 M. The 1st order graph resulted in k=0.006152 (Figure 1: Graph 1). Other groups also resulted in their decolorization of CV to be the 1st rate

The Beers Law calibration experiment used many concentrations of crystal violet solutions. Each of these solutions were test and analyzed in order to determine the absorbance of each concentration The results were than graphed and produced a slope of 1.00E05 with an intercept of -2.21E-02.

Make sure to use the same type of cuvette to keep the width consistent and to prevent any experimental error from arising. Obtain 5 of the same type of cuvettes and pre-rinse them thoroughly. Label them numbers one through five in increasing molarity. Then, fill each of the cuvettes with one of the five solutions you created back in Part A. We will first examine the solution that exhibits the highest concentration or molarity. Make sure to wipe the outside of the cuvette with a Kimwipe before placing into the SpectroVis Plus device. Observe the graph that is generated and make sure to take note where the maximum absorbance takes place.

5. The degree of precision was to 3 significant figures obtained with the spectrophotometer. The major source of error in our experiment was not calibrating the spectrophotometer with distilled water.

2. In order to calculate the density of a solid or liquid sample, what measurements are needed?

(Lab: A Penny For Your Thoughts). The density of a matter is equal to the mass divided into the volume. The mass of a matter or object can be found by using a scale. Furthermore, the volume can be found using the method of water displacement. The purpose of finding

In Measuring and Understanding Density, several experiments were performed to find density of regularly shaped objects, irregularly shaped objects, liquids and gasses. An additional experiment was done to find the specific gravity of a sampling of liquids. The purpose of the experiment was to provide a better understanding of density and to be able to extrapolate unknowns based upon these calculations. The experiments yielded data in keeping with Kinetic-molecular theory in regards to the density of water versus its temperature. Key measurements and formulae were also used to determine densities of metal and plastic objects as well as irregularly shaped rocks. It is possible to find the density of an object (be it liquid, gas or

To begin, we formulated a method in which each unknown substance and compound were compared to find their molar relationships. In the experiment we calculated the molar mass of every compound by determining the amount of moles per gram in each element using the periodic table and then added them together. We then

The spectrophotometer was turned on 15 min prior to the experiment. For each different intensity levels, 2 cuvettes were prepared (one for the experimental variable and one for the control variable). Also, 2 cuvettes were prepared for each different wavelength. Two blanks were prepared for the entire experiment (one for intensity, one for wavelength). The experimental cuvette for intensity consisted of 2.5 ml of 2.5 ml DCPIP, 2.0 ml water, 2.0 ml PO4 buffer, and 0.2 ml chloroplasts, a total of 6.7 ml. The control cuvette for intensity was the same as the experimental cuvette for intensity. The experimental cuvette for wavelength consisted of 2.5 ml DCPIP, 1.7 ml water, 2.0 ml PO4 buffer, and 0.5 ml chloroplasts a total of 6.7 ml. The blank cuvette intensity contained 4.5 ml of water, 2.0 ml of PO4 buffer, and 0.2 ml chloroplasts for a 6.7 ml. The wavelength blank was composed of 4.2 ml water, 2.0 ml PO4 buffer, and 0.5 ml chloroplasts for a 6.7 ml. Before starting the experiment, we set the wavelength at 600 nm, placed the blank cuvette into the spectrophotometer, and set the absorbance at zero. The laboratory was kept dark during the experiment to prevent light pollution.

The purpose of this lab was to identify unknown substances using density. We had three unknown substances; a yellow liquid and two metal rods. For each substance we measured volume using the water displacement method in a graduated cylinder and mass using a triple beam balance. Then we calculated density using the formula density (g/cm3)= mass (g)/volume (cm3). The data we collected in the lab is in the table below. After comparing our data with the density chart we were able to determine the identities of the substances. The liquid was cooking oil and the rods 1 and 2 were copper and aluminium, respectively. In conclusion, density - a characteristic property- is important because even though many substances may look the same but have different