Lab 5 MW

Ammonium sulfate is added to an unknown mixture of ions. A precipitate forms. The solution is centrifuged, and the remaining solutions is decanted. Ammonium oxalate is then added to the solution and no precipitate forms. Sodium monohydrogen phosphate and sodium hydroxide are added to the decanted solution, and no precipitate forms. Sodium hydroxide is added to a fresh sample of the unknown. A damp piece of litmus paper over the opening of the test tube remains red. Select the ions present.   Question 5 options:   Ba2+   Ca2+   Mg2+   NH41+

Ammonium sulfate is added to an unknown mixture of ions. A precipitate forms. The solution is centrifuged, and the remaining solutions is decanted. Ammonium oxalate is then added to the solution and no precipitate forms. Sodium monohydrogen phosphate and sodium hydroxide are added to the decanted solution, and no precipitate forms. Sodium hydroxide is added to a fresh sample of the unknown. A damp piece of litmus paper over the opening of the test tube turns blue. Select the ions present.   Question 4 options:   Ba2+   Ca2+   Mg2+   NH41+

Gravimetric analysis of Fe3O4 (MW = 232 g/mole) may be undertaken with the following reactions:  Fe3O4 → Fe2O3 → Fe (OH)3. Weight of sample containing 8.00% Fe3O4 that must be taken to obtain a precipitate of Fe(OH)3 (MW = 107 g/mole) that weighs 150 mg is . a.  0.108 g  b. 0.325 g c. 1.355 g d. 4.065 g              Amount of Fe2O3 (MW = 160 g/mole) from which 150 mg of Fe(OH)3 (MW = 107 g/mole) may be obtained is .              a.  0.112 g              b.  0.224 g              c.  0.448 g              d. none of the other choices

1. Calcium in a sample solution is determined by atomic absorption spectroscopy (AAS). A stock solution of calcium is prepared by dissolving 1.834 g CaCl, 2H,0 in water and diluting to 1 litre. From this stock solution, the second stock solution is prepared by the dilution factor of 10. Three standard solutions of calcium are prepared from the second stock solution with the following dilution factor: 20 (first standard solution), 10 (second standard solution) and 5 (third standard solution). A blank solution is prepared as well. Absorbance signals of AAS are as follows: 1.5 (blank solution), 10.6 (first standard solution), 20.1 (second standard solution), 38.5 (third standard solution), 29.6 (sample solution). (Molar mass; Ca = 40.00 g mol-, CI = 35.45 g mol-, 0 = 16.00 g mol-', H = 1.00 g mol-1) a. Construct ONE (1) plot that could be used to represent the calibration curve. b. From the plot of Q1a, determine the amount of calcium in parts per million.

A 0.2500-g of dry CaCO3  was completely dissolved into a solution of 5-mL conc. HCl and 50-mL distilled water in an erlemeyer flask. The resulting solution was boiled for 5 minutes to expel CO2 from the reaction, and then it was cooled to room temperature and the solution was transferred in a 500-mL volumetric flask filled to volume by rinsing the erlenmeyer flask and combining all the washings to fill the mark. A 5.0-mL aliquot of the CaCl2 solution was taken from the orignal solution and was transferred into an erlenmeyer flask with 10-mL NH3 buffer, 20-mL distilled water, and 5 gtts of EBT. The solution consumed 4.96 mL of an EDTA solution. MW: CaCO3 = 100.1   Compute for the N EDTA solution.         0.0053 N         0.0531 N         0.5313 N         None of the choices

Dilution is necessary for commercially available acids such as HNO3, H2SO4 etc so that the strength is reduced to be used by students in a chemistry laboratory. Select one: O True O False

an Q soda (NaHCO3)is used.often.as Bocking antiacid to neudralize hydvechlovic acid of Stomach.angd.cachof soclium.chlorideg. Carbon oliaxide and Watex are resulted 08: 30 00: 00 00:30 10:00 farom this reaction.while magnesium. hydvoxide Ma CotHD2 is also usedl as entiacid to produce waderand magnesium chlaride. For Iamof cach of NalHcoz aud.Ma(ot)2. (At.wt Na- 23,H=1,C=12,0= 16, Mg =26 ). 01.:0 each f them is more epfectiveas.antiacid 10:30 11:00 11:30 12:00 p.m. 12:30

Solution and explanation for Percentage Yield and Theoritical Yield for this data (Synthesis of Aspirin) Salicylic acid - 1.950 g Labeled watch glass - 50.664 g Labeled watch glass & piece of filter paper together - 50.872 g filter paper only - 0.208 g Where the data is from: https://youtu.be/tLXljLxRZ0U Room temperature - filter paper, watch glass and aspirin - 53.088 g

Solve for the chemical reaction specified. Thanks in advance.

1. A 1.2040 g sample containing sodium carbonate and inert material was dissolved in water and titrated to methyl orange end point, requiring 32.50 mL of 0.1020 M HCl. Calculate the %Na2CO4 in the sample. a. 93.36% b. 14.59% c. 12.75% d. 23.41%2. A 0.1510 g KHP (MW = 204.22 g/mol) sample required a volume of 57.04 mL of NaOH solution to reach a phenolphthalein end point. Calculate the molarity of NaOH titrant. a. 0.02593 M b. 0.006481 M c. 0.01296 M d. 0.01012 M

A sample of processed meat scrap weighing 4.000 g is digested with concentrated H.SO. and Hg(catalyst) unti the Npresent has been converted to NHHSO.. This is treated with excess NaOH, and the liberated NHs is caught in a 100-ml of H.SO. ( Iml = 0.01860 g Na:OJ. The excess acid requires 57.60 ml of NaOH ( Iml = 0.12660 g potassium acid phthalate, KHCaH.O.j. Calculate the percentage protein in the meat scrap

30jud to 28AM basu mw 5. Sodium carbonate is a reagent that may be used to standardize acids in the same way that you have used KHP in this experiment. In such a standardization it was found that a 0.498-g sample of sodium carbon- ate required 23.5 mL of a sulfuric acid solution to reach the end point for the reaction.

Preparation of 0.25N HCl Objective: Apparatus and Materials: Procedure: Compute for the volume of HCl needed to prepare 0L of 0.25N HCl. Using a graduated cylinder, measure the computed volume of HCl. Pour it into the volumetric flask that is half- filled with distilled water and agitate. Add enough distilled water until it reaches the mark. Transfer the solution to the reagent bottle. Add again distilled water until it reaches the mark and pour it to the same reagent bottle, thus making the total volume of 1.0L. Label the reagent bottle.   Data and Computations:       Conclusion:

Dilution is done to commercially available acids such as HNO3, H,SO4 etc so that the strength is increased and so it will be safe to be used by students in a chemistry laboratory. Select one: O True O False

12:19 1 4 7 +/- The oxidation number of oxygen in 0²- is 2 5 8 Question 13 of 17 . 3 60 9 O Submit Tap here or pull up for additional resources XU x 100

The same physical property that helps drive the reaction to completion can also stall out the reaction before it starts.  What do we do in the procedure that helps minimize this concern?

explain why pressure reduction reduces gas solubility

14. What mass of barium nitrate is dissolved in 31.29 mL of a 4.78 M solution? please show work

-NEUTRALIZATION REACTIONS Can you help me with this one? The given problem is in the image that I've attached 1.  Based on the given problem, What is the molecular weight of potassium biphthalate (C8H5KO4)? 2.Based from the given problem, what is the mEq of potassium biphthalate? 3.Based from the given problem, what is the Normality of the sodium hydroxide solution? Would you please provide a separate solution to each question, thankyou!     Here are the instructions on how will you write the answers: 1. All answers to be entered via short answer are in the NUMERICAL FORMAT and presented up to the 3rd decimal place. ADD TRAILING ZEROS if necessary, to complete your answer. NO NEED TO INCLUDE THE UNIT for now.For uniformity of answers, please be guided by the following examples:- If your answer is 5.627594, enter 5.628- If your answer is 3.129934, enter 3.130- If your answer is 8.38, enter 8.380- If your answer is 1.2, enter 1.200- If your answer is 25, enter 25.000- If your answer is…

Questions 15-21 concern the reaction 2 SO2(8) + 102(8) 22 SO3(g), the crucial step in the production of sulfuric acid. For this reaction AH° = -198 kJ/mol and AS° = -0.187 kJ/mol·K. SO2 (perhaps from the production of copper metal) is mixed with air and heated, resulting in the formation of SO3. (All concentrations are in Kolks units.)

4. Determine the molarity of a solution prepared by dissolving 155.6 g of citric acid, C3H5O(COOH)3, in water and then diluting the resulting solution to 4500.0 mL. please show work

From 0.8 av. lb of 20% w/w KOH solution, 72.6 O 121 142 86.2 Next g of 12 percent w/w KOH may be produced.

1.750 g öf HBF ih 250.0 ML of 1410 aqueous solution der the following reacti.. 8. You are asked to make 250.0 mL of a 1.5 M solution of H2SO4 in lab. You have a stock solution of 10.0 M H2SO4 available to you. How do you make the solution? + 9. Consider the balanced reaction in 1b above. If you begin with a 150.0 mL of a 1.3 M solution of NH&OH and excess CuSO4, how much Cu(OH)2 will you produce? MacBook Pro DII F9 F10 F3 F4 F5 F6 F7 F8 @ 2# 2$ 2 3 4 5 8 W R Y この LL

True or False. Write the word “reducing” if the statement is correct, otherwise write “non-reducing”. 6.  Ethanol (95%) & 10% TCA are used to precipitate glycogen from the solution.