TERM TEST II (March 13th 2020)

Amylum, commonly known as starch is a white powder with variable molecular formula due to the different number of repeating sugar units based on the plant that it is obtained from. A sample of amylum in the form of spherical beads was subjected to series of analyses to determine physicochemical properties in the quality control unit of a factory. From the results each bead is found to have a 4.5 mL volume and 1.47 g/mL density. 4 of the beads were placed in a reaction chamber combusted, as a result, 43.1 g CO2 and 14.7 g H2O were obtained. If the molecular weight of the amylum is 972.84 g/mol how many repeating units the starch molecule consist and what is the molecular formula of the starch? [Empirical Formula=CxHyOz, Repeating unit=n, Molecular Formula=( CxHyOz)*n= CnxHnyOnz]

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Standard deviation- 0.0371 mL, 0.0392 mL, 0.0392 mL, 0.03887 mL, 0.0398 mL Mean- 0.194 mL

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Part C: Determination of the alcohol content of unknown liquor St tiend Volume (mL) Sample ТИШТИНА 0.00% alcohol 10.0% alcohol 20.0% alcohol 40.0% alcohol 50.0% alcohol Unknown Mass (g) 1o podina ko 9.8919 9.7899 9.600 9 9.420 д % Alcohol content of the liquor_ 9.2155 9.5089 2VLELA CVOLION EAEK EVI OK DRA IVBOKY LOBAN ocen 10.00 10.00 10.00 10.00 10.00 10.00 Density (g/mL) 0.00% alcohol calculation: ися → о 0.99 во 0.99 Ino7 sm dolaW 120.00 supinubst sdi na LANG 411 be: [scordas: 0.97 0.94 in oil to notisalarisi 0.92 0.95

Explain the difference between random sampling and haphazard sampling as used in Analytical chemistry.

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Choose the one correct or one incorrect statement regarding filtration:      gravity filtration uses a Buchner funnel, filtering flask and negative pressure      filter paper should be wet with solvent to seal it to the funnel before filtering      the solution collected in the filtering flask is called the residue      vacuum filtration is most often used to remove impurities from a solution      the solution to be filtered should completely fill the top of a Buchner funnel

PAPER CROMATOGRAPHY • Define chromatography • Demonstrate an understanding of the process of chromatography • Describe the steps involved in a chromatography investigation Explanation Coloured inks are often made up of several different inks. Each colour of ink will get carried a different distance by the water, allowing you to see all of the different inks. Try this with different colours to see what actually goes into a colour. This technique is called chromatography and can be used in chemistry to find out what is in an unknown mixture. II. Materials .Felt tip pens (non-washable) . Kitchen roll .A bowl or cup . Water • Scissors III. Health and safety • Make sure that you thoroughly clean any equipment after the experiment before using for food IV. Procedure Method 1 1. Take a sheet of kitchen roll and draw a simple picture with a non-washable felt tip pen. 2. Place the sheet over an empty bowl. This is to keep the paper from getting too wet. 3. Carefully add a few drops of water…

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Instructions You are required to produce a short lab report using the information given in the accompanying document, ‘Lab report assessment_student data’. This document introduces an experiment, and also provides a set of experimental data for this experiment. You are required to use this data to perform steps 8 and 9 of the procedure. This includes calculations of a particular value, and then comparison to the true value. Consider any experimental errors when comparing calculated values and true values. Your report should be between 300 and 500 words (including all table contents and titles of tables and graphs). Your lab report should consist of three sections only: • Experimental • Results and Discussion • Conclusion You do NOT need to include an introduction section. Your experimental section should be written in appropriate lab report format, (passive voice, 3 rd person, in paragraphs). Your results and discussion section should contain the data presented in table format, and…

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)

Read the scenario below. Identify what is inappropriate lab behavior in each instance. Then write the appropriate lab safety technique. Kendra is heating a test tube for an experiment using a Bunsen burner. She didn't put on safety goggles since she already wears glasses. She tilts the test tube mouth away from her towards her lab partner, since the steam keeps fogging up her glasses.

The spectroscopic data in the table is generated with five solutions of known concentration. Concentration (M) 0.0133 m= 0.0266 0.0532 0.106 0.213 Absorbance 0.1271 What is the intercept of the linear regression line? 0.08531 0.5388 1.069 Use a spreadsheet program, such as Microsoft Excel, to graph the data points and determine the equation of the best-fit line. 1.954 What is the slope of the linear regression line formed by these points? M-1

New employees at Avondale Industries’ unmanned systems production line in Denver, CO, participate in employee training under the direction of the training and development department, but the line managers conduct the actual training. During the last two trainings, the line managers cut the sessions short and explained that the employees would receive better training while working on the production line. The trainer responsible for the program understood the line managers’ viewpoint about developing skills used on the line but needed them to see that training should provide more than just developing those specific skills. Which of the follow statements best explains why training should provide a longer-term view than just teaching line workers the skills needed to perform satisfactorily in their current jobs?     Giving line workers expanded training helps them understand more than specific skills; it also helps them become more confident contributors.   Training with a…

We want to inform you that your performance as a tutor is being evaluated and will be reported to the administration. Additionally, there will be an online ranking system that not only assesses the overall performance of Bartleby as a website but also ranks individual tutors based on their question-and-answer accurate contributions. This ranking will be shared with management. Please ensure that your responses are of the highest quality, as multiple requests may be directed to the same person for assessment.

We want to inform you that your performance as a tutor is being evaluated and will be reported to the administration. Additionally, there will be an online ranking system that not only assesses the overall performance of Bartleby as a website but also ranks individual tutors based on their question-and-answer accurate contributions. This ranking will be shared with management. Please ensure that your responses are of the highest quality, as multiple requests may be directed to the same person for assessment.

We want to inform you that your performance as a tutor is being evaluated and will be reported to the administration. Additionally, there will be an online ranking system that not only assesses the overall performance of Bartleby as a website but also ranks individual tutors based on their question-and-answer accurate contributions. This ranking will be shared with management. Please ensure that your responses are of the highest quality, as multiple requests may be directed to the same person for assessment.

We want to inform you that your performance as a tutor is being evaluated and will be reported to the administration. Additionally, there will be an online ranking system that not only assesses the overall performance of Bartleby as a website but also ranks individual tutors based on their question-and-answer accurate contributions. This ranking will be shared with management. Please ensure that your responses are of the highest quality, as multiple requests may be directed to the same person for assessment.

We want to inform you that your performance as a tutor is being evaluated and will be reported to the administration. Additionally, there will be an online ranking system that not only assesses the overall performance of Bartleby as a website but also ranks individual tutors based on their question-and-answer accurate contributions. This ranking will be shared with management. Please ensure that your responses are of the highest quality, as multiple requests may be directed to the same person for assessment.

Part C: Determination of the alcohol content of unknown liquor Stretien Volume (mL) Sample ТИШТИНА 0.00% alcohol 10.0% alcohol 20.0% alcohol 40.0% alcohol 50.0% alcohol Unknown Mass (g) 1o podina ko 9.8919 9.7899 9.600 9 9.420 д % Alcohol content of the liquor_ 9.2155 9.5089 2VLELA CVOLION EAEK EVI OK DRA IVBOKY LOBAN ocen 10.00 10.00 10.00 10.00 10.00 10.00 Density (g/mL) 0.00% alcohol calculation: ися → о 0.99 во 0.99 Ano 7 si dotaW 120.00 supirmbest sdi na LANG 411 be: [scpoidas: 0.97 0.94 in oil to notisalarisi 0.92 0.95

We want to inform you that your performance as a tutor is being evaluated and will be reported to the administration. Additionally, there will be an online ranking system that not only assesses the overall performance of Bartleby as a website but also ranks individual tutors based on their question-and-answer accurate contributions. This ranking will be shared with management. Please ensure that your responses are of the highest quality, as multiple requests may be directed to the same person for assessment.

A chemist working as a safety inspector finds an unmarked bottle in a lab cabinet. A note on the door of the cabinet says the cabinet is used to store bottles of carbon tetrachloride, diethylamine, pentane, acetone, and tetrahydrofuran. The chemist plans to try to identify the unknown liquid by measuring the density and comparing to known densities. First, from his collection of Material Safety Data Sheets (MSDS), the chemist finds the following information: liquid density - 3 1.6 g·cm carbon tetrachloride diethylamine - 3 0.71 g·cm pentane 3 0.63 g cm 3 0.79 g cm acetone tetrahydrofuran - 3 0.89 g cm Next, the chemist measures the volume of the unknown liquid as 1.427 L and the mass of the unknown liquid as 894. g. Calculate the density of the liquid. Round 3 your answer to 3 significant digits. |lg.cm Given the data above, is it possible to identify the liquid? yes no carbon tetrachloride diethylamine If it is possible to identify the liquid, do so. pentane acetone tetrahydrofuran