Chapter 19 Test

Could someone Please Help with these! No plagiarism Please! A tire inflated with air is an example of a ___________________________. Evidence - Explanation - A pellet of sodium (Na) sliced in two pieces is an example of a _____________________________. Evidence - Explanation -

An analysis where we know what analytes we are looking for is called An analysis where we do not know what analytes are in the sample is called a An example is A) untargeted, confirmation, targeted, Comprehensive drug screen B) targeted, confirmation, untargeted, comprehensive drug screen C) targeted, comprehensive drug screen, untargeted, confirmation analysis. An example is analysis. ▪ True or false: The purpose of the internal standard is to make quantitation of the analyte insensitive to injection errors

• Stock solution: 1000 mg/L Target sample concentrations: 50-400 mg/L • Create a 5-point standard dilution to cover the test • If each test only needs 10 mL, make plans to make the dilution so you have 20 mL of each concentration. ·

STANDARD SAMPLE PREPARATIONS FOR ABSORBANCE & CONCENTRATION DATA Concentration of stock nickel sulfate hexahydrate solution = .400 Molarity Sample Volume Absorbance Concentration (In Molarity) a 5 mL .179 10 mL .329 15 mL .588 20 mL .760 25 mL .939 Reference Blank = 0 Please show how to find Molarity, please show steps. Thank you and stay safe.

The density of the first fraction collected would be expected to be close to a value of ______.     1.00 g./mL     0.895 g/mL     0.789 mL     0.950 g.mL

charting costs ($) - T T TTT T 2. On the graph shown to the right: (a) Draw a star (*) on the abscissa. 120 110 100 (b) Draw a diamond (O) on the ordinate. 90 9 80 70 (c) Draw a circle around the dependent variable. 60 50 40 30 (d) Draw a small arrow point- ing to a tic mark. 20 10 25 30 35 (e) Circle the origin. 10 16 20 number of patiernts

Did the control experiment verify or refute the results from Exercise 1? Use the results from Exercise 1 and 2 to validate your answer. (Experiment 1 is exercise 1)

Activity 4: Aromatic Water Peppermint water (Simple solution method) Formula Peppermint oil ___ Purified water  ___ To make          60ml Materials: Erlenmeyer flask, filter paper Procedure: (Provide the procedure)

Using the data provided please help me answer this question.  Determine the concentration of the iron(Ill) salicylate in the unknown directly from to graph and from the best fit trend-line (least squares analysis) of the graph that yielded a straight line.

HDPE and PS are both inert to bases and acids, which plastic would you rather chose to put 1 Liter of 6M HCl for general chemistry lab? Explain why.

Use the "Statistics" function of your calculator to find the mean and standard deviation for the data.  (Round to tenths.)  Mean:_______  Standard deviation:_________  Use the Normal Probability Distribution table or the built-in functions of your calculator to find: a. What percent of teen adults are taller than 6 feet (72 inches)?  What percent of teen adults are taller than 5 feet (60 inches)?

How do I complete table 4 with the date given in table 3?

NaOH is the base (please elaborate) Thank you!

Please correct answer and don't use hand rating

As a material expands its weight per unit of volume (also called density) _______ ? Group of answer choices Changes unpredictably Decreases Increases Stays the same

The beaker below BEST represents a(n) ______________. Assume the particles are surrounded by water molecules that are not shown for clarity.

Think about the situation where you are investigating the relationship of study time vs. exam grade.a. Which variable would be on the x-axis (and why)?b. Which variable would be on the y-axis (and why)?c. Would you expect the slope to be positive or negative (and Why)? 2) Contrast and compare interpolation with extrapolation. Which is “safer” to use and why?3) Look up how “the best fit straight line” is constructed. The term “Least squares” should be in your explanation.4) If I plot some data and end up with a r2 of (-) 0.99, is my plot useless? Explain.

V. Error Analysis/Questions For the following questions explain what specific error in calculating your Ksp value would occur (i.e. would the Ksp be too HIGH or too LOW), compared to the situation in which no errors occur. When you answer the question, consider how the situation affects the calculation of Ksp. Each answer must have an explanation and type the answer, please. A. The buret was not conditioned (it still had water in it) when you add the HCl. Would the Ksp be too HIGH or too LOW? B. There was Ca(OH)2 solid (that was not filtered off) in your solution to be titrated. Would the Ksp be too HIGH or too LOW? C. You measured 24.00 mL of Ca(OH)2 solution instead of 25.00 mL. Would the Ksp be too HIGH or too LOW? D. The HCl concentration was actually lower than the reported molarity on the bottle. Would the Ksp be too HIGH or too LOW?

Which of these statements regarding dissolved gas analysis is incorrect? Select one: A. For low temperature faults methane and hydrogen are generated B. As the temperature of the fault increases, ethane is produced reducing the methane content   C. At higher temperatures methane starts increasing overtaking the ethane content and ultimately becomes predominant D. Moisture content is measured is as free and dissolved levels