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sorry this is the first time i used wikianswers but this is my question? i need help please:
A forensic chemist tests a water sample for cyanide. To do so, the sample is diluted by pipetting 1 mL into an empty 100 mL volumetric flask, which is then filled to the mark with deionized water. If the measured concentration was found to be 0.637 mg/L, what was the concentration of the original sample. Give your answer in ppm.
Enter your answer in the box provided to 3 significant figures.
For very large or small numbers, use scientific notation (e.g. 1.23e-4).
Do not enter units.
What else can I help you with?
What is the formula on how to find starch in water?
To find the concentration of starch in water, you can use a spectrophotometric method by measuring the absorbance of the solution at a specific wavelength. Prepare a standard curve using known concentrations of starch solutions to correlate absorbance with concentration. Then, measure the absorbance of your sample and use the standard curve to determine the starch concentration.
Why should the concentration of sample be low in spectrophotometer readings?
When doing reading on a spectrophotometer, the sample being studied is either a color change or a precipitated compound, depending on the wavelength that it is being read. If it is a precipitated compound and it has a very high concentration, then you run the risk of the light being used to measure the absorbance not going through. In which case you have total absorbance but it is inaccurate in helping you determine the concentration of your sample because you are unsure where the concentration limit is for that wavelength, and your sample could possibly be able to absorb more. In which case you still can't calculate the concentration of the sample.
What does the value of absorbance on a spectrophotometer mean?
Absorbance on a spectrophotometer is a measure of the amount of light absorbed by a sample at a specific wavelength. It provides information on the concentration of a substance in the sample since absorbance is directly proportional to concentration according to the Beer-Lambert law. A higher absorbance indicates greater absorption of light, which can be used to quantify the concentration of the absorbing species in the sample.
What is the mass of a sample containing 5.82 mol of zinc?
378.3g You multiply the RMM by the Concentration (mol) Mass(g)=Concentration(mol)*RMM
What is the purpose of serial dilution in serology?
Serial dilution in serology is used to determine the concentration of an antibody or antigen in a sample by making a series of dilutions with a known dilution factor. This allows for the creation of a standard curve to quantify the concentration of the target molecule. Serial dilution helps ensure that the concentration of the sample falls within the detectable range of the assay.
What is the a280 protein concentration in the sample?
The a280 protein concentration in the sample is 2.5 mg/mL.
How can the calibration curve of absorbance versus concentration be used to determine the concentration of a substance in a sample?
The calibration curve of absorbance versus concentration can be used to determine the concentration of a substance in a sample by measuring the absorbance of the sample and comparing it to the absorbance values on the calibration curve. By finding the corresponding concentration value on the curve, the concentration of the substance in the sample can be determined accurately.
What is the nanodrop protein concentration of the sample being analyzed?
The nanodrop protein concentration of the sample being analyzed is the measurement of the amount of protein present in the sample using a nanodrop spectrophotometer.
How can we accurately determine the protein concentration in a sample using measuring protein concentration techniques?
To accurately determine protein concentration in a sample, techniques such as spectrophotometry, Bradford assay, and BCA assay can be used. These methods involve measuring the absorbance of light by the sample and comparing it to a standard curve to calculate the protein concentration.
How can one calculate the original concentration from dilution?
To calculate the original concentration from dilution, use the formula: C1V1 C2V2. Where C1 is the original concentration, V1 is the original volume, C2 is the final concentration, and V2 is the final volume. Rearrange the formula to solve for C1: C1 (C2V2) / V1. This will give you the original concentration.
What is the process for performing HPLC calculation of concentration in a sample?
To perform HPLC calculation of concentration in a sample, first, prepare the sample and inject it into the HPLC system. The sample will pass through a column where the compounds separate based on their properties. The detector then measures the amount of each compound in the sample. By comparing the peak area or height of the compound to a standard curve of known concentrations, the concentration of the compound in the sample can be calculated using a formula.
How can one accurately measure protein concentration in a sample?
One can accurately measure protein concentration in a sample using methods such as spectrophotometry, Bradford assay, or BCA assay. These methods involve measuring the absorbance of light by the proteins in the sample and comparing it to a standard curve to determine the concentration.
Why is a titration performed?
Titration is performed to determine the concentration of a substance in a solution. It involves reacting two solutions - one with a known concentration and the other with an unknown concentration - until they reach an equivalence point, allowing for the calculation of the unknown concentration.
How to find the concentration of a diluted solution?
To find the concentration of a diluted solution, you can use the formula: C1V1 C2V2. This formula relates the initial concentration (C1) and volume (V1) of the original solution to the final concentration (C2) and volume (V2) of the diluted solution. Simply plug in the known values and solve for the unknown concentration.
What is the concentration of the substance in the sample, measured in um to ng/ml?
The concentration of the substance in the sample is measured in micromoles per nanogram per milliliter (um to ng/ml).
How can one calculate the original concentration from a given dilution factor?
To calculate the original concentration from a given dilution factor, you can use the formula: Original concentration Final concentration / Dilution factor. This formula helps determine the initial concentration of a solution before it was diluted.
How does atomic absorption spectroscopy work to analyze the concentration of elements in a sample?
Atomic absorption spectroscopy works by passing a light beam through a sample containing the element of interest. The atoms in the sample absorb specific wavelengths of light, which are then measured to determine the concentration of the element in the sample.
