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Consider four distinct physical properties: boiling point, melting point, solubility, and density. Which of these physical properties do you think allows thin layer chromatography (TLC) to work? Choose one then, explain your reasoning.

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.

In a test tube, dissolve 10 drops of methanol in 3 ml. of water. Oxidize a copper wire spiral by passing it through a Bunsen burner. Plunge the red-hot wire into the alcohol solution several times, cooling the solution under the tap (faucet) so as not to evaporate too much of it. Next, add 1 drop of 0.5% resorcinol solution. Measure 2 ml. of concentrated sulfuric acid (CAUTION!) and pour this carefully down the sides of the test tube containing the mixture. Note the color of the zone intermediate between the acid and the solution.   RESULT:

How to determine the difference between primary , secondary and tertiary alcohol in the laboratory

Dissolution Distilled H20 Concentration 0.01 M HCI Concentration (mg/ml) Time Total amount A Total amount A (mg/ml) (mg) (mg) 5 0.16 0.1 10 0.24 0.18 15 0.35 0.25 20 0.48 0.34 25 0.58 0.4 30 0.67 0.5 1. Plot the given data on an ordinary paper and find the slope for each line then calculate the IDR constant for aspirin in the two dissolution media, water and HCI. NOTE: Slope of the calibration curve = 1.0 (mg/ml and saturation solubility of salicylic acid is equal to 2.0 gm/L.

Table 2: Absorbance Values of Standards and Unknowns. Sample Blank Standard Solution 1 Standard Solution 2 Standard Solution 3 Standard Solution 4 Standard Solution 5 Water Sample 1 Water Sample 2 Phosphate Concentration (in ppm) Y17 0 ppm 0.02 ppm 0.04 ppm 0.08 ppm 0.16 ppm 0.32 ppm Freeman Lake 0.001 0.325 0.292 0.413 0.315 0.039 0.054 0.049 Absorbance at 2= 690 nm Calculations: 1. Construct a phosphate standard curve in Excel by plotting concentration (in ppm) on your x-axis and Absorbance (unitless) on your y-axis for your known solutions. Label the axes on the graph and provide the curve with a title. Use a linear trendline to generate a best fit line to your data. Label the graph with the equation and the R" value. Insert your labeled graph in the space below. X

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?

Pre-lab question #8: Suppose you were dissolving a metal such as zinc with hydrochloric acid. How would the particle size of the zinc affect the rate of its dissolution? As the particle size of the zinc increases, the rate of dissolution AA (decreases/increases).

You obtain an Unknown Sample from the Stockroom.  You begin testing the solution through the steps outlined in the flowchart of the experiment’s PDF file.  You first add HCl and centrifuge your mixture.  You observe the formation of a white precipitate in the bottom of the test tube.   After pouring off the supernatant liquid, you add hot water to the white precipitate.  Addition of the hot water dissolves some of the precipitate, but some white precipitate still remains on the bottom of the test tube.  You pour off the supernatant liquid, and add ammonia (NH3) to the remaining precipitate.  You now observe the formation of a gray-black precipitate. Which of the following is a valid conclusion to draw at this point? Select one:     Hg22+ is definitely present.   Pb2+ is definitely present.   Ag+ could be present, or Hg22+ could be present, or BOTH could be present.   Ag+ is definitely present

You obtain an Unknown Sample from the Stockroom.  You begin testing the solution through the steps outlined in the flowchart of the experiment’s PDF file.  You first add HCl and centrifuge your mixture.  You observe the formation of a white precipitate in the bottom of the test tube.   After pouring off the supernatant liquid, you add hot water to the white precipitate.  Addition of the hot water dissolves some of the precipitate, but some white precipitate still remains on the bottom of the test tube.   Which of the following is a valid conclusion to draw at this point?     Pb2+ is definitely present.   Hg22+ is definitely present.   Ag+ could be present, or Hg22+ could be present, or BOTH could be present.   Ag+ is definitely present

Current Attempt in Progress From the curves shown in Animated Figure and using the following Equation, determine the rate of recrystallization for pure copper at the several temperatures. Make a plot of In(rate) versus the reciprocal of temperature (in K-1). (a) Determine the activation energy for this recrystallization process. (See Section FACTORS THAT INFLUENCE DIFFUSION.) (b) By extrapolation, estimate the length of time required for 50% recrystallization at room temperature, 20°C (293 K). (a) i kJ/mol (b) i days

30 20 10 From the procedure 2. Assemble the simple distillation apparatus as generally shown in Figure SD.1 in the lab manual, ensuring that the thermometer bulb is aligned at, or slightly below, the Y in the distillation head. Each ground joint is greased by putting three or four stripes of grease lengthwise around the male joint and pressing the joint firmly into the other without twisting. 3. Attach a water condenser to the distillation head. 4. Remember, water goes in the bottom and out the top. Attach a clamp holder to the end of the drain tube to keep it weighted in the drain. Turn water to a trickle. If it is slowly draining, it is high enough. Begin a low flow of water through the condenser. 5. Place the set up on a heating/stir plate. 6. Turn on the hot plate to start heating the solution. Monitor the temperature and the boiling of the solution throughout the distillation process. 7. Record the temperature of the distillate when the first drops are recovered. 30.0 8. Adjust…

Define Extraction in chemistry  ?

1. Solubility Test Table 1. Results for the solubility test. OBSERVATION* INFERENCE SAMPLE Ethyl acetate ** Нехаne Methanol Water Coconut oil Vitamin E Beef fat Miscible (soluble) or immiscible (insoluble) ** polar or nonpolar Sudan IV Test Table 2. Results for Sudan IV test. OBSERVATION* INFERENCE SAMPLE Нехаne Ethyl acetate Methanol Water ** Coconut oil Vitamin E Beef fat Homogeneous or heterogeneous mixture ** polar or nonpolar

3. The Maximum Acceptable Concentration (MAC) of Pb in drinking water is 10 ppb. If a sample hasconcentration of 65 nM, what will be the concentration in ppb and does it exceed the MAC?a. 8 ppb, no it didn’t exceed the MACb. 9 ppb, no it didn’t exceed the MACc. 12 ppb, yes it exceeds the MACd. 13 ppb, yes it exceeds the MAC

50 mL of stock solution were taken and added to flask. Then 50 mL of Di water were added to the flask. This is solution 1. Then 50mL of solution 1 were taken and added to a flask and 50 mL of Di water were added to the flask. This is solution 2. Then 50mL of solution 2 were taken and added to a flask and 50 mL of Di water were added to the flask. This is solution 3. Then 50mL of solution 3 were taken and added to a flask and 50 mL of Di water were added to the flask. This is solution 4. Find the concetrations of each solution.  Information of stock solution - molar mass- 534.3g/mole 0.587g in MilliQ

1. 500.0 mL 0.2 M KI2. 500.0 mL 0.2 M KCl3. 500.0 mL 0.1 M K2S2O84. 500.0 mL 0.1 M K2SO45. 500.0 mL 4.0 mM Na2S2O3 (from Na2S2O3∙5H2O)pls compelete the 2nd table given the data

What are the types of gravimetric methods? Give an examples where each method is used in an analysis. What is particulate gravimetry? When do we use this technique?

A 0.1 g amine-containing compound is dissolved in water then diluted to 100 mL. You subject it to spectroscopic analysis, in order to get the concentration of amine in this compound. Next, you get 1 mL of the previously diluted sample then dilute it again to 250 mL for measurement. Then, you fill 3/4 of a 1-cm cuvette with this diluted sample, and you run an analysis using an AAS. The recorded absorbance is 0.545 at 410 nm. What is the molecular weight of the compound? (The molar absorptivity is 1.23 x 104 cm-1 mol-1 L.)

When purifying a sample of aspirin that was produced in the lab, the impure aspirin sample should be dissolved in a very cold solvent, so that solid impurities can be filtered and analyzed the next day or the next week. True or False?

Pre Lab Questions: (Each answer is to be written as a complete sentence) What is the reason for washing the precipitate with water in Step 9? Define precipitate. Define filtrate. In Step 2, what is the purpose for rinsing the stirring rod? read the Procedure to answer the questions  Using a balance, mass between 1.50 – 2.00 grams of sodium carbonate in a pre-massed 150mL beaker. Add 20 mL of distilled water and stir thoroughly to make sure all the crystals are dissolved. Rinse the stirring rod with a little distilled water after stirring. Using a balance, mass between 1.50 – 2.00 grams of calcium chloride dihydrate in a pre-massed 50 mL beaker. Repeat Step 2 for the solution in the 50 mL beaker. Pour the calcium chloride solution into the 150mL beaker containing the sodium carbonate solution and stir. Mass a piece of filter paper. Fold the filter paper and place it into the funnel. Wet it with a little distilled water to ensure that it is stuck to the sides of the funnel. Slowly…

Different type of methods used in household contaminated wastewater purification

2. Questions: 1. CHM-202 Lab 2 Freezing Point Depression Rev2 G6-2022 10/14 From your understanding of colligative properties, how would you design an experiment to measure the freezing point of a material which freezes at -2 °C using the same apparatus used in this laboratory and any chemical reagents commonly found in a chemical laboratory. Ice is the only material you have available to cool the solutions. If you measured the boiling point of the solution used in Trial 4, would you predict it would have a boiling point equal to, higher than, or lower than the boiling point of pure cyclohexane? Explain your answer.

Which of the following are properties of a good recrystallization solvent? Check all correct answers. Group of answer choices boiling point of solvent < melting point of crystals boiling point of solvent > melting point of crystals Crystals are soluble in solvent at low temperature and soluble at high temperatures. Crystals are soluble in solvent at high temperatures but insoluble or slightly soluble at low temperatures. Solvent boiling point is about room temperature. Impurities should be either soluble at all temperatures or insoluble at all temperatures. An abundant amount of crystals must be recoverable from the solvent.

A student was given a stock ascorbic acid solution of 2.323 mg/L. Following the directions in the lab, the student obtained the data below. Calculate the concentration of ascorbic acid in the Standard (in microgram/L, ug -). Report your answer with one place after the decimal. initial final initial volume final volume volume volume color reagent color reagent stock stock solution solution solution solution Standard 1.35 mL 6.64 mL 5.12 mL 9.32 mL

PART 3- LABORATORY EQUIPMENT EQUIPMENT NAME FUNCTION To hold test tubes. Attaches to a retort stand to support glassware being heated. To pour liquid from a large container into a small container. To provide a flame during an experiment. ones To light the Bunsen burner. To attach test tubes to a retort stand. To clean substances out of a test tube. To hold a hot crucible or flask. To hold a hot test tube. To place on the lab bench to prevent burning or to use with ring clamp. To transfer small amounts of liquid. To grow bacteria or contain small experiments. To hold liquids. To measure liquids. To contain experiments (a stopper can be used to close the flask). To hold a hot beaker. To perform an experiment with a different substance in each well. To hold chemicals and perform experiments in. To scoop and transfer small amounts of substances, To stir during experiments that involve mixing or dissolving.

The unknown salt you will be identifying is composed of one of the 6 anions and one of the 6 cations studied during previous weeks of lab. However, the list is not endless. An obvious physical property can be used to eliminate some salts. Another physical property can imply or eliminate possibilities as well. During this lab, what are two physical properties that can be used?

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

All changes save 7. When two solutions are mixed, a color change occurs. The data tables show the time between mixing and the color change for two sets of conditions. For Condition One, the solution concentrations were constant and temperature varied. For Condition Two, the temperature was constant and concentrations varied. Condition One: Concentration Time for Temperature (°C) Sample Color to Change 1 10° 36 sec 22° 14 sec Condition Two: Temperature Time for Concentration Sample Color to % Change 1. 100% 15 sec 2. 50% 24 sec Which of these statements is true according to the data? O The reaction rate is greater at 22°C than at 10°C. O Reducing the temperature increases the rate of the reaction. The reaction is affected by changes in temperature not by changes in concentration. O Decreasing the concentration increases the reaction rate. PREVIOUS 17 of 25 NEXT SAVE & EXIT