Extra Credit Assignment

DDT (molar mass = This ban was brought about due to the persistence of DDT in many different ecosystems, leading to high accumulations of the substance in many birds of prey. The insecticide was shown to cause a thinning of egg shells, pushing many birds towards extinction. If a 20-L drum of DDT was spilled into a pond, resulting in a DDT concentration of 354.49 g/mol) was a widely used insecticide that was banned from use in the United States in 1973. 8.66 x 10-5 M, how long would it take for the levels of DDT to reach a concentration of 1.41 x 10-7 M (a level that is generally assumed safe in mammals)? Assume the decomposition of DDT is a first-order process with a half-life of 56.0 days. Time =|| days

4PH3 P4 + 6H₂ What is the rate of disappearance of PH3 from 0 to 75 seconds? Time [PH₂] [P4] [H₂] 0 2.00 0 0 75 1.50 ? ? 150 1.25 0.19 1.13 225 1.13 0.22 1.31 300 1.07 0.23 1.40 RatepH3 [?] x 10 M/s Coefficient (green) Exponent (yellow) Enter

[12!initial Two trials were completed in a kinetics experiment, resulting in the data collected below. Calculate the rate of each trial using the change in iodine concentration: rate Enter your answers in the boxes, rounded appropriately for significant figures. Use scientific notation, with E in the place of x10. For example, 1234 would be entered as 1.234E3 and 0.00123 would be entered as 1.23E-3. Do not use units. Trial Acetone, M 12, M H*1, M Time (sec) Rate 1 1.8 0.0025 0.33 136 2 1.8 0.0025 0.66 71 What are the units of rate? Use symbols only in your answer. What is the order of the reaction with respect to hydrogen ion? Report your answer to the tenths place. What is the order of the reaction with respect to hydrogen ion rounded to the nearest whole number?

V. Reaction of Sodium carbonate (N22CO3) with hydrochloric acid Reaction NazCO3 and HCI Observation for the Bubbles formed (fast), fizzing sound reaction Balance the chemical equation Na,CO3 (aq) + HCI (aq) NaCI (aq) + CO2 (g) +H,0 (1) Identify type of reaction Question: What happen to the glowing wood splint when it is inserted inside the test tube? Explain. 4

Use the information given here to answer both questions (4 and 5).  For the fictitious reaction:  AB → A + B Some data was collected measuring the [AB] at certain time intervals.  This data was then graphed as described below. A graph of 1/[AB] versus time (s) gives a straight line with the equation: y = 0.0052x + 0.1135 and a R2 = 0.9995.  A graph of ln[AB] versus time (s) gives a straight line with the equation: y = -0.0068x + 1.725 and a R2 = 0.8925.   Assume the data doesn't fit a zero order reaction. What is the rate law for this reaction? Select one: a. Rate = k[AB]2 b. Rate = k[A][B] c. Rate = k[AB] d. Rate = k   Using the data from the previous question. What is the value of the rate constant for the given reaction? Select one: a. k = 0.0052 M-1s-1 b. k = 0.0157 Ms-1 c. k = 0.0068 s-1 d. There is no way to determine the value of the rate constant from the given information.

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Name (please print): Fall 2022 Basic Laboratory Operations Post Lab Questions 1.) Suppose you're attempting to measure the density of a liquid that is highly volatile (it evaporates quickly). If you first measure the mass and then several minutes later you measure the volume of the liquid will the measured density be higher than the true value, lower than the true value, or the true density of the liquid. [It helps to understand this problem with the density equation.] 2.) Suppose you're attempting to measure the density of a liquid that is highly volatile (it evaporates quickly). If you first measure the volume and then several minutes later you measure the mass of the liquid will the measured density be higher than the true value, lower than the true value, or the true density of the liquid. [It helps to understand this problem with the density equation.] 3.) You're attempting to calculate the density of an alloy. The alloy is in the shape of a cylinder. If the mass of the alloy is…

you need extra neip. Good luck! Your progress has been saved Question 5 of 10 Study the reactions. 1. C (s) + O2 (9) → CO, (g) 2. H2 (9) +02 (g) → H2O (1) 3. C3 Hs (g) + 502 (g) → 3CO2 (g) + 4H2O (1) 4. 3C (s) + 4H2 (g) C3 Hs (g) AH = -394 kJ AH = -286 kJ AH = –2220 kJ AH; = ? What is the enthalpy of formation of C3H3(g) in Reaction 4? O 212k) O-212 k) O 106 kJ 2-106 kJ

All changes saved 17 Allyson and Cami add 25 mL of 3 M hydrochloric acid (HCI) to beakers containing 0 mL, 25 mL, 50 mL, and 75 mL of distilled water. The students then drop 5 cm of Magnesium (Mg) ribbon into each beaker and measure the time for the magnesium to completely react with the acid. The results are shown in the data table. W Y. 125 mL 125 mL 125 mL 125 mL 100 mL 100 mL 100 mL 100 mE 75 mL 75 mL 75-mE 75 mL 50 mL 50-mL 50 mL 50 mL 25-mL 25 mL 25 mL 25 mL Magnesium and HCI Reaction HCI Water Time Beaker (mL) (mL) (s) W 25 8. 25 25 16 25 50 23 Y 25 75 33 17 of 25 NEXT SAVE&EXIT PREVIOUS Which statement BEST explains the change in reaction time as the amount of water increases? US 7:18 Lit & 8.

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How Long it Might Take for PFOA Blood Levels to Decline Assumes a 3-year half-life (Micrograms per Liter) 100 Average PFOA Levels in Blood (Micrograms per Liter) 3M Workers, Decatur, AL 1,125 This figure estimates a 3-year half-life of PFOA levels in blood at different starting levels of exposure. PFOA levels decrease by about half every two to four years. 90 Dupont Workers, Parkersburg. WV 410 80 C8 Study: Little Hocking. OH 228 A half-life is the amount of time it takes C8 Study: Lubeck, wV 92 for PFOA levels in blood to be reduced 70 by half. C8 Study: Tuppers Plains, OH 42 * The level shown for PFOA in blood for the Hoosick Falls area is the geometric mean and is based on test results for 2,081 participants including people using Village water, people using private wells, people who work in the area, and former residents. 60 Hoosick Falls area, NY I 23.5* C8 Study: Mason County, WV I 16 50 U.S. Population Geometric means are a way of calculating the middle level. They are used in…

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