The active ingredient in a zinc nutritional supplement is ZnSO4·7H2O (molar mass = 287.58 g/mol). Ten zinc tablets containing a mix of the active ingredient and an inactive filler were ground and mixed together thoroughly. The total mass of these ten tablets was 10.165 g. A 1.830 g sample of the finely ground tablets was dissolved in an acidic solution. The solution was neutralized with ammonia and subsequently warmed in a water bath. Addition of (NH4)3PO4 to the solution resulted in the precipitation of ZnNH4PO4. The precipitate was filtered and dried, then ignited to produce 0.234 g of Zn2P2O7 (molar mass = 304.76 g/mol). What is the mass percent of ZnSO4·7H2O in each tablet?
What is the average mass of the active ingredient ZnSO4·7H2O and inactive filler in each tablet?
In: Chemistry
HOI + NO = I2 + NO3-1 balance the following reaction in acid
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Naphthalene is mostly insoluble in water. How would you recrystalize benzoic acid contaminated with naphthalene?
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At 1 atm, how much energy is required to heat 49.0 g of H2O(s) at –10.0 °C to H2O(g) at 119.0 °C?
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Technetium-99 is used as a radioisotope in a variety of medical applications . if a patient receives a dosage of 6.00 mg at 8 am on thursday , then how much would remain at 4pm on friday afternoon? the half life of Tc-99 is 6.0 hours.
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What are the benefits and drawbacks in CZE (Capillary Zone Electrophoresis) with other more conventional separation technique, such as HPLC (High Performance Liquid Chromatography)?
In: Chemistry
In: Chemistry
In: Chemistry
A buffer solution was prepared by dissolving 4.00 grams of sodium propanate (NaCH3CH2CO2, FM 96.06 g/mol) in a solution containing 0.100 moles of propanoic acid (CH3CH2CO2H) and diluting the mixture to 1.00 L. pKa for propanoic acid is 4.874.
(a) To this solution was added 5.00mL of 1.00 M HCl. Calculate the pH of the resulting solution.
(b) To this solution was added 5.00mL of 1.00 M NaOH. Calculate the pH of the resulting solution.
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can someone please give me name, structure and percebtage of FAME that are likely produces from the vegetable oil? i need 3! and it has to be similar to the fatty acid structure of vegetable oil!
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Use the Henderson–Hasselbalch equation to calculate the pH of each solution:
Part A
a solution that is 16.5 g of HF and 22.0 g of NaF in 125 mL of solution
Part B
a solution that contains 1.23% C2H5NH2 by mass and 1.30% C2H5NH3Br by mass
Part C
a solution that is 15.0 g of HC2H3O2 and 15.0 g of NaC2H3O2 in 150.0 mL of solution
In: Chemistry
| a |
Suppose hydrogen atoms absorb energy so that electrons are excited to the n = 7 energy level. Electrons then undergo these transitions, among others: (a) n = 7 to n =1 (b) n = 7 to n = 6 (c) n = 2 to n = 1 Enter the letter (a, b, or c) for each. the smallest energy? the highest frequency? the shortest wavelength? |
| b |
What is the frequency of a photon resulting from the transition n=6 → n=1? h = 6.62 × 10-34 J·s s-1 |
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Starting with a ccp array of anions, what structure types are generated by a) filling all tetrahedral sites with cations, b) filling half of the tetrahedral sites, e.g. T+, with cations c) filling all octahedral sites with cations and d) filling alternate layers of octahedral sites with cations? Comment on the absence of any known structure type in one of these four categories.
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Deep water fish are hard to transport to the surface safely. Why do you think that is?
As the water pressure decreases, there is not enough oxygen for the fish in the water
As the water pressure increase, the air in the swim bladder compresses until they burst.
As the water pressure decreases,the air in the swim bladder compresses until they burst. Is it this one... and explain why or why not
As the water pressure decreases,the air in the swim bladder expand. until they burst.
In: Chemistry
The Determination of Magnesium by Direct Titration
Preparation of Solutions:
Buffer solution, pH 10: Diluted 57mL of NH3 and 7g NH4Cl totaling 100mL solution
Eriochrome Black T: Dissolved 102.4mg in 15mL ethanolamine and 5mL of absolute ethanol
EDTA: 3.8008g of purified dihydrate Na2H2Y 2H2O, mixed with distilled water to total volume of 1L
I received a Magnesium Sulfate unknown, and diluted it to 500mL with distilled water then transferred 3 50mL aliquots to separate conical flasks and added 2mL of pH10 buffer and 4 drops of Eriochrome Black T to each flask and titrated each with 0,01M EDTA until I reached the endpoint. My 1st resulted in 19.23mL of EDTA used, 2nd 19.26mL EDTA and 3rd was 19.25mL EDTA used.
During this, I was not given the weight of the unknown Magnesium Sulfate. I am confused on how to determine the unknown Magnesium Sulfate, and express the results as ppm of Mg2+ in the unknown sample.
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