Questions 2-4 refer to the absorption spectrum for a 0.80 M solution of metal M2+ and a calibration curve for the metal M2 collected in a 1.5 cm cuvette, shown in Figures 2 and 3. 0.9 1.4 0.8 1.2 0.7 1 0.6 0.8 0.5 0.4 0.6 0.3 0.4 0.2 0.2 0.1 1.2 0 1 0.8 0.6 600 550 650 0.4 450 500 700 400 0.2 0 [M2+] (M) Wavelength (nm) Figure 2. Absorption spectrum of 0.80 M M2+ Figure 3. Calibration curve for M2+ 2. At what wavelength was the calibration curve obtained? Use the data from both graphs to explain your choice. 3. Would the value of the molar absorptivity (a) be greater, lesser or equal for M for the absorbance of light at 400. nm vs. 650. nm. Use the data from Figure 2 to explain your choice. 4. Using the calibration curve in Figure 3: A sample of a solution of unknown concentration of M2 has an absorbance reading that is "off scale" because the absorbance was measured to be above 0.8. You dilute this sample by adding 5.0 mL of water to 1.0 mL of the solution of M2*. The absorbance of the diluted solution was determined to be 0.35 at the same wavelength used for the calibration curve. What is the concentration of M2, in M, of the original undiluted sample? Absorbance Absorbance

SHOW WORK. Convert the following energy measurement to the unit shown. Answer the questions related to the setup and calculation for this problem. 6.21 x 102 cal to kJ Write your work on paper showing all conversion factors, unit cancellation, and final answer with proper sig figs and units. Use this work to answer the intermediate question(s). Use the three blanks to enter the value, exponent, and unit (in this order) that appears in the numerator of the cal/J conversion factor. Calculate the answer and use the three blanks to report the answer in decimal notation with proper sig figs, value, and units.

The density of an unknown substance is 3.08 g/ mL. If the volume is 4.56 what is the mass of this sample show work?

What laws of thermodynamics does the Escher´s drawing violates? Explain.

Use the References to access important values if needed for this question. In the laboratory a student finds that it takes 706 Joules to increase the temperature of 13.3 grams of liquid water from 23.0 to 36.4 degrees Celsius. The specific heat of water calculated from her data is J/g°C. Submit Answer Try Another Version 1 item attempt remaining Visited Previous Next Cengage Learning | Cengage Technical Support 10 10 MAR étv 27 MacBook Air

Determine the efficiency of a machine that requires 2059 J of work and produces 1892 J of work. O 108.8% 100% 8.2% O 91.9%

Part A A piston has an external pressure of 15.0 bar. How much work has been done in joules if the cylinder goes from a volume of 0.160 litres to 0.470 litres. Express your answer with the appropriate units.

Mass of water in the uncalibrated region (g) Temperature of water (°C) Temperature (°C) Volume of 1 g water at temperature reported (mL) 18 Volume of the uncalibrated region of the buret (mL) 19 20 21 22 23 24 25 steel weights. 26 Volume (mL) 1 1.0024 1.0026 1.0028 1.0030 1.0033 Using the appropriate temperature dependent value of 1.0000 g water from Table 1, determine the volume of the water in the uncalibrated region of your buret. Use the volume value closest to your temperature value. 1.0035 1.0037 1.0040 1.0043 0.401 23.0 Unrounded 3 3 Rounded 3