What is the equilibrium concentration of Ni^2+ (aq) in the solution. If one millimole of Ni(NO3)2 dissolves in 220.0 mL of a solution that is 0.300 M in ammonia?

mass of Na2S2O3 is 1.220g

titration of bleach with Na2S2O3 solution:

trial 1: total volume used 66mL

trial 2: total volume used 73.8mL

Density of Bleach 1.074 kg/L

a) find the moles of Na2S2O3 used to titrate the bleach solution

b)find the moles of I2 formed by reaction with bleach

c) find the molarity of OCl- present in the bleach solution

d) find the grams of NaOCl present in the bleach

e) find the percent NaOCl present in the bleach

What is the molarity of a solution containing 13.7 grams of NH3 in 1.55 liters of solution?

Calculate the pH of a 0.100 M sodium benzoate, NaC6H5CO2, solution. The Ka of acetic acid is 6.3 x 10-5

The vapor pressure of benzene is 73.03 mm Hg at 25 °C. A nonvolatile, nonelectrolyte that dissolves in benzene is cholesterol.  

Calculate the vapor pressure of the solution at 25 °C when 5.507 grams of cholesterol, C₂₇H₄₆O (386.6 g/mol), are dissolved in 205.6 grams of benzene.

benzene = C₆H₆ = 78.12 g/mol.

VP(solution) = ____ mm Hg

Fill out table and show all calculations

Final             Volume of              Volume of               Volume of       Final volume (uL)

[PNPP] mM   0.5mM PNPP(ul)   0.2M Tris-HCl(ul)   enzyme (uL)

0.01                                                                            100                        1500

0.02                                                                             100                       1500

0.04                                                                             100                         1500

0.06                                                                            100                            1500

0.08                                                                            100                              1500

0.1                                                                           100                             1500

0.2                                                                              100                               1500

0.3                                                                           100                               1500

0.4                                                                             100                                1500

1.

Phosphorus pentachloride is formed when phosphorus trichloride and chlorine react.

PCl_3(g) + Cl_2(g) ⇌ PCl_5(g)

The equilibrium constant for the reaction is K_C = 35.9 at 119 °C. If 0.489 mol of phosphorus trichloride is added to 0.802 mol of chlorine in a 1.08-L reaction vessel at this temperature, what is the equilibrium concentration (in mol/L) of phosphorus pentachloride?

2.

Nitric oxide is formed in automobile exhaust when nitrogen and oxygen in air react at high temperatures.

N_2(g) + O_2(g) ⇌ 2 NO_(g)

The equilibrium constant for the reaction is K_P = 0.242 at 1200 °C. If a container is charged with 0.243 atm of nitrogen and 0.101 atm of oxygen and the mixture is allowed to reach equilibrium, what will be the equilibrium partial pressure of nitrogen?

3.

Consider reaction (1) shown below with it's associated equilibrium constant. What is the equilibrium constant for reaction (2)?

Report your answer to THREE significant figures.

   (1)     A + 3 B ⇌ 2 C , K = 0.259

   (2)    2 A + 6 B ⇌ 4 C , K = ??

The pressure-based equilibrium constant for the reaction shown below is K_P = 3.575 at 443 °C. What is the value of K_C at this temperature?

2 NO_(g) + O_2(g) ⇌ 2 NO_2(g)

If you have a 4.00 mg sample of a radionuclide known as Q-234, calculate the mass that will remain after 5.00 years given that the half life of Q-234 is 2.5 years.

Remarkably, a catalytic system that uses light energy to hydrolyze water into hydrogen H2(g)and O(g) has been devised (Science 334, 2011: 645-648) to capture and efficiently store solar energy. Hydrogen is "clean burning" in that it yields only H2O. In this problem you will contrast the combustion of 1 kgH2(g) to that of 1 kg of n-octane.

a. Calculate the enthalpy change on burning 1 kg of H2(g) to H2O(l) at 25∘C and 1 bar

b. Calculate the entropy change on burning 1 kg of H2(g) to H2O(l) at 25∘C and 1 bar.

c. Calculate the free-energy change on burning 1 kg of H2(g) to H2O(l) at 25∘C and 1 bar.

d. Calculate the enthalpy change on burning 1 kg of n-octane(g)to H2O(l) and CO2(g) at 25∘C and 1 bar.

e. Calculate the entropy change on burning 1 kg of n-octane(g)to H2O(l) and CO2(g) at 25∘C and 1 bar.

f. Calculate the free-energy change on burning 1 kg of n-octane(g) to H2O(l) and CO2(g) at 25∘C and 1 bar.

1.

a) Calculate the solubility of Pb3(PO4)2 in water.

b) Calculate the solubility of Hg2Br2 in water and in 0.300 M CaBr2. Explain why the solubilities are different in water and in 0.300 M CaBr2.

An unknown compound contains only carbon, hydrogen, and oxygen. Combustion analysis of a 1.893 gram sample of the compound produced 5.545 grams of carbon dioxide and 1.388 grams of water. The 1.893-gram sample contained 7.002 x 10-3 moles. What is the molecular formula for this compound?

Trying this one again too... it's a completely different question, I need to know how to make the (100 ml) solution.

Glacial acetic acid is 99.5% acetic acid (f.w. 60.052) by weight and has a density of 1.05g/mL.

Describe the operations needed to prepare exactly 100 ml of 0.100M pH 5.000 buffer, using the dry salt sodium acetate and the liquid glacial acetic acid.

If 10 mL of 0.025 M benzoic acid (K_a = 6.5 * 10^-5) is titrated with 0.01 M NaOH, what is pH after 0 ml, 20 ml, 50 ml, and 90 ml of base have been added?

Questions for Crystal Violet Lab.

1. Give the derivation of a first order rate equation and show why the plots of Ln ([dye]_o/[dye]_t) vs t should be linear.

2. What property other than [dye]_t and [dye]_o could have been used for the plot of Ln ([dye]_o/[dye]_t) vs t? Explain your answer.