CHEM 270 Lab 1 _Pipetting and Volumes

20,18,2,4,15,15,10 Using these data, construct a 80% confidence interval for the average net change in a student's score after completing the course. Assume the population is approximately normal.  Construct the 80% confidence interval. Round your answer to one decimal place.

A pipet delivers 10.9 mLmL , 10.1 mLmL , and  10.9 mLmL  in consecutive trials. Find the mean volume of the samples.  =  Answer = 10.6 mL Part B What is the average deviation from the mean for the above samples?

An oil sample had its iodine number determined using the pyridinium tribromide method. The sample and reagents used are as follows: Oil sample: 0.19 mL, density: 0.954 g/mL Pyridinium tribromide: 0.472 g Na2S203: 0.1 M, endpoint 27.68 mL %3D What is the approximate Bromine Number? O 138 89 O 120 O 200

To run a spectrophotometry experiment, begin by warming up the spectrophotometer and preparing the samples. Be sure to select the correct absorbance (X), then run a measurement on the sample solution. Follow up by running measurements on sample solutions. Once data is collected, turn off the instrument, clean the area, and discard the samples. Partially correct (2 of 4 correct)

Make a dilution series to get to 1:100. Start with making 1:10 dilution by adding 1mL of sample and 9mL of diluent, now continue the series to get to 1:100

Color BEFORE adding Color AFTER adding Intensity of color AFTER adding FeCl3 Test Tube # FeCl3 FeCl3 #1 (salicylic acid) clear lilac 100% #2 (commercial aspirin A) clear slightly pink 50% #3 (commercial aspirin B) clear lilac 95% #4 (aspirin from your clear pink 20% synthesis above) #5 (control) clear clear 0% Based on this data and the melting point of Aspirin, how pure is the synthesized product?

Can I get detailed explanation for this table , mentioning the apparatus and when’s the timer is started ? What happens next

1. The concentration of NaOH from the best three of your trials. 2. The average concentration of 3 of your trials (only use 3 trials) 3. The standard deviation of your 3 trials [If you have a calculator with stats on it, you can use that/bring it to class, but for the lab report you will have to write out your calculations.] 4. Your PPT.

7. A piper delivers 10.4 mL , 10.2 mL, 10.8 mL , and 10,6 mL consecutive trials . Find the mean volume and average deviation from the mean.

Which of the statements below are TRUE regarding the mean and standard deviation? I.    As the number of measurements increases, x̄ approaches μ if there is no random error.II.    The square of the standard deviation is the average deviation.III.    The mean is the center of the Gaussian distribution.IV.    The standard deviation measures the width of the Gaussian distribution.

Consider the following sets of replicate measurements: (1) Calculate the mean and standard deviation of Group A. (2) Determine the confidence interval at 95% confidence level. Assume the data here are the only knowledge you have and no previous measurements are available.

I need help understanding how to do this, can you please show me how you get the CFU/mL

Estimate the absolute deviation and coefficient of variation. (The numbers in parentheses are absolute standard deviations)

I need help to calculate this data please thanks a lot

Calculate the mean and standard deviation. 4.10(+0.02) x 0.0050(+0.0001) 1.97(+0.04)

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A sample of rainwater was collected from four separate locations across theMetroplex. Each sample was measured once by two separate methods for the presence ofsulfate. Determine whether the two methods are equivalent with respect to giving thesame answer for [SO42-].