Discussion about: Chemistry and Health

Smog is the pollution of the atmosphere over large cities with a mixture of nitrogen Oxide (NO, NO2) gases and Ozone (O3) gas. These gases are produced by burning gasoline in the internal combustion engines of our cars. Suggest a solution(s) to reduce the emission of these gases to the atmosphere.

Please make sure to type it.

what is the handbook value of the concentration of calcium carbonate in hot water?

Use critical temperature and pressure for oxygen gas to determine critical molar volume assuming
a) ideal gas  L/mole
b) van der Waals gas  L/mole
c) Redlich-Kwong gas  L/mole

Sally chemist is attempting to determine the mass % of acetic acid in vinegar. Below is an excerpt from her lab book:

A. Prepared vinegar analyte

25.0 mL vinegar

mass of vinegar 25.20 grams

added 75.0 mL H₂O

added 2 drops phenolphthalein

temperature: 27.0 ^oC

manufacturer's mass % acetic acid = 3.5 %

B. Prepared burette

filled with standardized NaOH solution 0.201 M

C. Titration

initial burette reading: 5.12 mL

final burette reading: 78.67 mL

solution is light pink

1. What is the density of her vinegar samlpe?

2. Use the manufacturers reported mass % acetic acid to estimate how many moles of acetic acid are present in her analyte.

3. Use your result from 2 to estimate how many mL of standardized NaOH solution she will need to reach the equivalence point.

4. Use Sally's data to calculate the molarity of acetic acid in her vinegar sample.

5 Use the results from 4 to calculate the mass % of acetic acid in Sally's vinegar sample.

what is the molarity concentration of lead cation in a saturated solution of lead sulfate? Ksp(PbSO4)= 6.3x10^-7 and what is the solubility of PbSO4 in g/ml?

show clear equations and answers

A 2.892 gram sample containing an unknown amount of arsenic trichloride and the rest inerts was dissolved into a NaHCO3 and HCl aqueous solution. To this solution was added 1.850 grams of KI and 50.00 mL of a 0.00937 M KIO3 solution. The excess I3

Calculate the adiabatic flame temperature for the following mixtures initially at 298 K: stoichiometric butane-air mixture, stoichiometric butane-oxygen mixture, 2.0% (by volume) of butane in air. Calculate without the restriction on the possible products using an online version of the CEA calculator developed by NASA and located athttp://www.grc.nasa.gov/WWW/CEAWeb/ceaHome.htm. Compare the results of the two calculations and explain possible differences.

A molecule has an ionizable group with a pK_a value of 8. At pH equal to 7.0, estimate roughly how much of the group is deprotonated (expressed as %)? Use 2 decimal points. Do not use scientific notation to enter your answer.

What is the K_sp in terms of the molar solubility s for the substance Fe (OH)₃?

A.s

B.s²

C.2s³

^D. 4s³

What is the precentage by mass of oxygen in CaCO3?

Calculate the pH of a 0.89 M methylamine solution.

In a procedure developed to determine the percent zinc in post 1982 pennies, 50 mL of an HCl solution was used to react (dissolve) all of the zinc in the penny. To ensure complete reaction, the solution contains twice as many moles of HCl that is usually needed. What concentration of HCl should be used? What is the amount in moles of excess (unreacted) HCl in solution? How many moles of NaOH would be needed to completely react with all of the excess HCl?

To determine the percent zinc in the penny, the excess was titrated with NaOH. determine the concentration of NaOH needed if you want to use approx 25 mL of NaOH to titrte the excess HCl.

calculate the % difference of the 0.5133g and 0.5275 g of struvite from the two water samples in question a. ----> two 10.0 Ml water samples were taking The procedure in this experiment is followed to determine the phosphate concentration. What would be the average phosphate concentration in the solution be( in units of molarity) if the student obtained 0.5133g and 0.5275g of struvite using gravimetric analysis? show all work assume this procedure precipitates out all of the phosphate from the sample in form of struvite