Lab 1_ Separation of Liquids by Distillation Procedure (1)

Consider the reaction below and answer the question below the reaction. A student performed a synthesis of ethyl 4-aminobenzoate (C) as shown in the reaction above. The student added 1.20 g of 4-aminobenzoic acid and 12.0 mL of ethanol together in the presence of sulfuric acid. The reaction mixture was heated to reflux for a period of 45 minutes. H₂N OH 4-aminobenzoic acid MM 137.14 g/m ol A + CH3CH₂OH ethanol MM 46.10 g/mol B ethyl 4-aminobenzoate ethanol H+ 4-aminobenzoic acid benzocaine none of the above H₂N OCH₂CH3 + H₂O Identify the limiting reagent of this reaction. Hint: the density of ethanol is 0.789 g/mL. ethyl 4-aminobenzoate MM 165.19 g/mol с

Consider the reaction below and answer the question below the reaction. A student performed a synthesis of ethyl 4-aminobenzoate (C) as shown in the reaction above. The student added 1.20 g of 4-aminobenzoic acid and 12.0 mL of ethanol together in the presence of sulfuric acid. The reaction mixture was heated to reflux for a period of 45 minutes. H₂N OH 4-aminobenzoic acid MM 137.14 g/m ol A 77.7% 56.1 % 128 % 72.2 % + CH3CH₂OH ethanol MM 46.10 g/mol H+ H₂N OCH₂CH3 + H₂O ethyl 4-aminobenzoate MM 165.19 g/mol C B Let's assume the theoretical yield of the reaction is 7.22 g and the student produced 5.61 g of ethyl 4-aminobenzoate. What is the percent yield of the reaction?

Consider the reaction below and answer the question below the reaction. A student performed a synthesis of ethyl 4-aminobenzoate (C) as shown in the reaction above. The student added 1.20 g of 4-aminobenzoic acid and 12.0 mL of ethanol together in the presence of sulfuric acid. The reaction mixture was heated to reflux for a period of 45 minutes. H₂N OH 4-aminobenzoic acid MM 137.14 g/m ol 2.44 g 1.21 g 3.24 g 1.45 g + CH3CH₂OH ethanol MM 46.10 g/mol B H+ H₂N OCH₂CH3 + H₂O ethyl 4-aminobenzoate MM 165.19 g/mol A с What is the theoretical yield for the reaction?

A sample (50 mL) of a bottled water was added to a 100 mL volumetric flask and then diluted to the mark. From this stock solution, 50 mL was taken, added to a 100 mL volumetric flask and diluted to the mark. Final concentration of the serial dilution: 587.7161ppm. 1. what is the concentration in the original bottle (ppm)

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

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

Data Sheet 4 ble gives the recommended mass of salt to dissolve in each of the four test tubes. Show a sample calculation for the solubility of KNO, using your actual mass from tube #1. Complete your graph on the back of this sheet. Solution # Recommended mass KNO3 Actual mass of KNO, (g per 5 mL H₂O) Solubility & KNO, 100 g H₂O Saturation temperature (°C) (g) 1 2.0 51.3 2.1971 2 62.5 4.0 11.1568 3 72.7 6.0 6.0112 83.6 4 8.0 806 Sample Solubility Calculation: Questions 1. According to your data, how does the solubility of KNO, change with increasing temperature? Does this indicate an endothermic or exothermic dissolving process? Explain. 2. Using your graph, indicate if each of these solutions would be saturated or unsaturated: a) 110 g of KNO3 in 100 g of water at 40 °C b) 60 g of KNO3 in 100 g of water at 70 °C c) 140 g of KNO3 in 100 g of water at 60 °C 3. According to your graph, what mass of KNO3 will dissolve in 100 g of water at 30 °C?

Consider the following scenario: 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:   1. Hg22+ is definitely present.   2. Pb2+ is definitely present.   3. Ag+ could be present, or Hg22+ could be present, or BOTH could be present. 4. Ag+ is definitely present

Given the following data/observations for experiment #43B [39B]: a. the mass of Benzyltriphenylphosphonium Chloride (BTPC)(limiting reactant) used was 0.486g. b. the observed melting point of the purified product was 145-149 °C. c. the mass of the purified product was 0.217 g. Calculate the theoretical and the percent yield of the purified product from the above data (show all appropriate calculations and units). Comment on the % yield and the purity of the purified product (included any appropriate errors to explain the results).

Constants Periodic Table Consider the following reaction: If the initial volume of the H2O2 solution is 3.2 L, what total amount of O2 (in moles) is formed in the first 20 s of reaction? Hint: Use Figure 1 to answer this problem. H2O2(aq) H20() + ½ O2(g) and the kinetics plots below to answer the questions to the right. Express your answer in moles to two significant figures. O 1.4 mol Figure 1. Plot of [H,O,] vs time O .8 mol 0.9 0.63 mol 0.8 0.7 O 0.70 mol 0.6 0.5 0.4 Submit Request Answer 0.3 0.2 0.1 Part B 20 40 60 80 time (s) concentration of H;O2 (mol L²)

POTASSIUM PERMANGANATE AND SODIUM HYDROXIDE Repeat procedure 3 using 6M sodium hydroxide instead of 6M sulfuric acid. Allow the solution to stand for about 15 minutes and write an observation of any changes. Observations: Balanced chemical equation: 2KMnO 4(aq) + 3NaHSO 3(aq) + NaOH (aq) → 2H2O(l) + K2SO 4(aq) + 2MnO 2(s) + 2Na2SO 4(aq) What substance is responsible for the color change?

Solution 1 Solution 2 Solution 3 Solution 4 Solution 5 Concentration iron(III) nitrate 0.00200 0.00200 0.00200 0.00200 0.00200 [Fe(NO3)3] (M) Concentration potassium thiocyanate 0.00200 0.00200 0.00200 0.00200 0.00200 [KSCN] (M) Volume Fe(NO3)3 (mL) 5.00 5.00 5.00 5.00 5.00 Volume KSCN (mL) 5.00 4.00 3.00 2.00 1.00 Volume DI water (mL) 0.00 1.00 2.00 3.00 4.00 Initial concentration [Fe3+] (M) 0.00100 0.00100 0.00100 0.00100 0.00100 Initial concentration [SCN‍] (M) 0.00100 0.000800 0.000600 0.000400 0.000200 Absorbance 0.269 0.192 0.154 0.104 0.052 Equilibrium [FeSCN2+] (M) 0.000198 0.000141 0.000113 0.0000765 0.000038 Equilibrium constant Kc Average Kc

5. Why is decantation rather than filtration the preferred method of separating the salt from the mixture? 12:03 AM

Select one answer for each question. For each question, the response write the rationale for selection as supportive. In a dynamic Brownian movement of particles in a sample solution, which of the following factor will fundamentally apply? A.Larger particles will move slower only in the beginning of the process, due to the presence of the smaller particles in the environment. B.Smaller particles will move rapidly based upon their own mass, and under the influence of solvent molecules. C.Both larger and smaller particles move at the same speed motion.

Assume we are to tackle a complex aqueous equilibria problem using the systematic process we learned in class.  In our example, we’re going to look at dissolving silver chromate (Ag2CrO4, Ksp = 1.2 x 10–12) in water.  Write 1 mass balance equation.

| ax NME /Chemical%20Reactions%20Asgn%202-5.pdf 9 Employee Home r4c Covenant Health Ca... Outlook.com - Free... S Birthday party politi. G what does it mea 1 / 2 100% Chemical Reactions-Write Neat and Balanced Reactions from Word Equations You need to submit one sheet of paper (not this one), that is very neat, with a fully balanced reaction for these 6 reactions Remember to include proper states. 1. solid potassium metal reacts with oxygen gas to produce solid potassium oxide. 2. solid potassium chlorate decomposes into oxygen gas and solid potassium chloride. 3. solid aluminum oxide is decomposed into solid aluminum and oxygen gas. 4. aqueous cobalt(III) nitrate reacts with solid zinc to produce aqueous zinc nitrate and solid cobalt.

The enzyme urease is widely used for determining urea concentration in blood. The Michaelis constant for urease at room temperature is 2.0 mM and k2 = 2.5 × 10^3 s^-1 at pH = 7.5. Based on the kinetic experiment, when 4.76 mM urease was used, the initial rate of the reaction was determined to be 8.1 M/sec. What is the concentration in unit of mM of urea in blood? Please keep your answer to two decimal place. Please convert all concentration unit to mM in calculation. The answer is 4.26 (I would need help getting this answer)