1. To prepare your ascorbic acid solution, you and your lab partner dissolved 121.34 g of ascorbic acid in a beaker with 50.00 mL of H2O. You and your lab partner then transferred the dissolved ascorbic acid to a 100.0 mL volumetric flask and filled the flask to the mark. What is the concentration of this 100.0 mL solution in mol/L? Then, you and your lab partner then transferred 5.0 mL of the 100.0 mL ascorbic acid solution to a clean 100.0 mL volumetric flask and filled the flask to the mark. What is the new concentration of this 100.0 mL solution in mol/L?

Although argon makes up 0.93 percent of the atmosphere, the gas evaded discovery until 1894, when physicist Lord Rayleigh and chemist William Ramsey identified it. The clues for the discovery of argon came from density measurements of nitrogen.

a) When Rayleigh prepared pure nitrogen from the decomposition of ammonia (NH3), he found that the nitrogen collected had a pressure of 1.0926 atm at 298.15 K. Use this data to calculate the correct density of nitrogen to four significant figures.

A quantity of N2 gas originally held at 3.80 atm pressure in a 1.00 L container at 26.0ºC is transferred to a 10.0 L container at 20.0ºC. A quantity of O2 gas originally at 4.75 atm and 26.0ºC in a 5.00 L container is added to the 10.0 L container already containing the N2.

a) Draw a diagram outlining this experiment, labeling the various quantities.

b) Calculate the total pressure in the new container.

c) What is the mole fraction of the nitrogen gas in the newly formed mixture?

Pertaining to the titration of 25.0mL of 0.100 M HCN (Ka=6.2x10-10) with 0.200 M NaOH, calculate the pH at the following points. a) initial pH, 0.0mL NaOH b) after the addition of 4.0mL NaOH c) after the addition of 6.25 mL NaOH d) at the equivalence point e) after the addition of 17.0 mL NaOH

a clock maker has 15 clock faces. each clock requires 1 face and 2 hands. If the clock maker also has 42 hands, how many clocks can be produced? If the clock maker has only 8 hands, how many clocks can be produced?

Calculate the pH of the final equilibrium mixture in each of the following solutions:

1. 10 mL of 0.005 M HNO₃ are mixed with 5 mL of 0.006 M NaOH [answer: pH=2.87]

2. One mole of HCl is mixed with one mole of ammonia (NH₃; k_b=1.76*10^-5) to form one liter aqueous solution. [answer: pH=4.62]

3. 0.5 moles of HCl is mixed with one mole of ammonia (NH₃; k_b=1.76*10^-5) to form one liter aqueous solution. [answer: pH=9.24]

4. One mole of hydrocyanic acid (HCN; k_a=6.2*10^-10) is mixed with one mole of potassium hydroxide (KOH) to form a one liter aqueous solution. [answer: pH=11.60]

5. One mole of hydrocyanic acid (HCN; k_a=6.2*10^-10) is mixed with 0.5 mole of potassium hydroxide (KOH) to form a one liter aqueous solution. [answer: pH=9.21]

6. 0.35 moles of ammonia (NH₃; k_b=1.76*10^-5), 01. mole ammonium nitrate (N₃H₄O₃), and 0.2 mole nitric acid are mixed to form one liter aqueous solution. [answer: pH=8.93]

A 7.70-L container holds a mixture of two gases at 35 °C. The partial pressures of gas A and gas B, respectively, are 0.190 atm and 0.891 atm. If 0.230 mol of a third gas is added with no change in volume or temperature, what will the total pressure become?

For two dimensional particle in a box, how many electrons can we get at most in the first energy level and why?

the Santa Ana winds are strong within Southern California. what drives this phenomenon?
(With respect to Gibbs and Helmholtz's eqn)
Physical chemistry question

A) How many grams of solid sodium fluoride should be added to 1.00 L of a 0.218 M hydrofluoric acid solution to prepare a buffer with a pH of 3.847 ?

grams sodium fluoride =  g.

B)How many grams of solid sodium hypochlorite should be added to 0.500 L of a 0.297 M hypochlorous acid solution to prepare a buffer with a pH of6.803 ?

grams sodium hypochlorite =  g.

C)How many grams of solid ammonium chloride should be added to 1.50 L of a 0.152 M ammonia solution to prepare a buffer with a pH of 8.330 ?  

grams ammonium chloride =  g.

How do you calculate the concentration in ppm from a gas chromatograph? The chromatograph is from a BTEX mixture and shows a peak for each component of the mixture. Bromobenzene was used as an internal standard. How can you calculate the concentration of each component using the ratios of peak area? Is there a specific equation for this?

Thank you!

A scientist dilutes 40.0 mL of a pH 5.85 solution of HCl to 1.00 L. What is the pH of the diluted solution (Kw = 1.0 × 10⁻¹⁴)?

a)     What are the molecules and ions doing in solution – are they static or moving around? 


b)    Can ions or molecules that are isolated from one another react? What must happen for them to react? 


c)     Why should the permanganate disappear faster if the concentration of H3O+(aq) is higher? 


d)    Devise a general, qualitative, statement about the effect that an increase in the concentration of a reactant has on the rate of a reaction, and an explanation of that effect. 


Chromium forms cubic crystals whose unit cell has an edge length of 288.5 pm. The density of the metal is 7.20 g/cm3. The atomic weight of Cr is 51.996 amu.
a) Calculate the number of atoms in a unit cell, assuming all atoms are at lattice points.
b) What type of cubic lattice does chromium have?
c) Calculate the radius of the Cr atom.
d) Calculate the empty volume of the cell.


Since I have the edge length, I'm pretty sure I cube that for volume and convert that to cm. Because I also have the density, I can use my calculated volume to find the mass. I also know the equation for this problem involves Avogado's number (6.022x10^-23) I just don't know how to find the answers to these questions, only an idea how to begin solving.

Can anyone help? Unfortunately there is no answer key so I can't even check if I'm right!

A solution is made by mixing exactly 500.0 mL of 0.167 M NaOH with exactly 500.0 mL of 0.100 M CH₃COOH. Calculate the equilibrium concentrations of H₃O⁺, CH₃COOH, CH₃COO^-, OH^-, and Na⁺.

[H₃O⁺] = M

[CH₃COOH] =    M

[CH₃COO^-] =    M

[OH^-] = M

[Na⁺] = M