What is the expected pH of a 0.250 M solution of oxalic acid with Ka = 5.37 x 10^-5 ([H+] = 0.002197) and will the pH increase by one unit if the solution is diluted to 0.0250 M?

Two aqueous solutions are at room temperature and are mixed in a coffee calorimeter. The reaction causes the temperature of the resulting solution to fall below room temperature. Whicch statement is true? A) This type of experiment provides data to calculate deltaErxn B)Energy is leaving the system during reaction C)The products have a lower potential energy than the reactants D) The reaction is exothermic E)None of the above is true

Hydrogen gas can be prepared by reaction of zinc metal with aqueous HCl: Zn(s)+2HCl(aq)→ZnCl2(aq)+H2(g) How many liters of H2 would be formed at 636 mm Hg and 17 ∘C if 27.0 g of zinc was allowed to react? How many grams of zinc would you start with if you wanted to prepare 6.85 L of H2 at 284 mm Hg and 28.5 ∘C?

Draw the process of the rusting of iron and note the 4-5 chemical ½ reactions. How do we prevent rusting?

Calculate E cell for the new conditons: How does the voltage change and why? (please explain using Le Chateliers principles)

Mg(s) , Mg+2(0.500M) ; Al+3 (2.500M), Al(s)

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An aqueous solution with a pH of 2.22 is diluted from 2.04 L to 3.92 L. What is the pH of the diluted solution?

Thanks in advance!

What is the [OH-] of a solution which is 0.18 M in ammonium ion and 0.10 M in ammonia?

The answer should be 1.0 x 10^-3. Please show al the work. Thanks!

Explain why the presence of crystals of the sample at the starting point causes streaking of the TLC plate during development.

Weak base/ Strong acid titration curve question.

1) In the titration of .0400 M weak base B of 50 ml with .100 M HCl. What is the solution pH before any HCl is added?

2) In the titration of .0400 M weak base B of 50 ml with .100 M HCl. What is the solution pH after 10 ml HCl is added?

3) In the titration of .0400 M weak base B of 50 ml with .100 M HCl. What is the solution pH at the equivalence point? (20 ml, at the equivalence point)

4) In the titration of .0400 M weak base B of 50 ml with .100 M HCl. What is the solution pH after 25 ml HCl is added?

*pKa of the conjugate acid of base is: 7.90

Solutions with a constant volume of 10.0 mL contain 0.750mg of dissolved tooth enamel plus variable concentrations of added Sr.

Added Sr(ng/mL=ppb) Signal(arbitrary units)
Added Sr: 0 , 2.50, 5.00, 7.50, 10.00

Signal: 28.0, 34.3, 42.8, 51.5, 58.6

a.) Find concentration of Sr and its uncertainty in the 10.0mL solution in ppb.
b.) Find concentration of Sr in tooth enamel in ppm.
c.) If the standard addition intercept is the major source of uncertainty, find the uncertainty in the concentration of Sr in tooth enamel in ppm.
d.) Find the 95% confidence interval for Sr in tooth enamel

I figured out a: 8.72 +/- 0.43 ppb, I just don't understand the rest

A wedding ring has a mass of 7.804 grams and is made of gold and silver. When the ring has been heated to 96.53

A. The activation energy of a certain reaction is 42.0 kJ/mol . At 29 ∘C , the rate constant is 0.0190s−1. At what temperature in degrees Celsius would this reaction go twice as fast?

B. Given that the initial rate constant is 0.0190s−1 at an initial temperature of 29  ∘C , what would the rate constant be at a temperature of 120.  ∘C for the same reaction described in Part A?

Please give the correct units too. Thank you!

a.You have 40.0 mL of a 0.100 M solution of HClO, with a K_a of 3.0 x 10^-8. b. What is the pH of the solution after the addition of 30.0 mL of 0.200 M NaOH?

A production facility heats various equipment using a network of heated air and water vapor lines. A boiler produces a 195.0 mol/hr stream consisting of 0.590 mol fraction of water and 0.410 mol fraction of air at 131.0°C and 5200.0 mmHg. The air and water vapor cool as the gases move away from the boiler, and steam traps collect and remove condensed water from the lines while the pressure remains constant.

a) If a total of 65.6 mol/hr of condensed water is removed from the air and vapor lines, what is the composition of the air and vapor mixture leaving the steam lines?

b) Use the Antoine equation for water valid between 60°C and 150ºC to find the temperature of the air and vapor mixture leaving the heating lines.

If 1.2 g of aspirin were dissolved in 100 mL of water, how much aspirin might you be able to recover if you were to extract the aqueous solution with 100 mL of dichloromethane? Also calculate the percent recovery.

If instead of extracing the aqueous layer with 100 mL of dichloromethane, what would have been teh percent recovery if you had used two sucessive 50 mL protions of dichloromethane?