@X@user.full_name@X@ @GMU: When 12.26 g of citric acid was dissolved in 108.4 g of benzene, the freezing point was 275.6 K. What is the formula mass of this compound? The freezing point depression constant for benzene is 5.12 (°C*kg)/mol. The melting point and boiling points are 5.50°C and 80.10°C, respectively.

@X@user.full_name@X@ @GMU: Determine the rate of the last set of reaction conditions. [A]o [B]o Rate, M/s 0.281 0.289 3.71e-5 0.433 0.289 7.08e-5 0.281 0.531 5.03e-5 0.433 0.444 ?

@X@user.full_name@X@ @GMU: The osmotic pressure of an unknown solution is 0.516 atm at 10.37 °C. Which of the solutions below is the most likely one? Assume any salt is completely ionic!

@X@user.full_name@X@ @GMU: Radioactive substances decay by first-order kinetics. How many days would be required for a sample containing neptunium-93 to decrease to 66.22% of its initial activity? The half-life of neptunium-93 is 2.35 days.

@X@user.full_name@X@ @GMU: Initially there were equilibrium concentrations of 0.1041 M A, 0.3333 M B, and 0.1041 M C. Which change will cause Qc to be greater than Kc? Use the reaction below.5A → 3 B +3 C Kc = 0.904

John Schreifels @GMU: When 0.1237 g of urea was dissolved in 106.3 mL of water, the osmotic pressure at 14.20°C was 0.4572 atm. What is the formula mass of this compound?

@X@user.full_name@X@ @GMU: What is the freezing point depression when 19.32 g of Ba(NO3)2 (formula mass = 199.30 g/mol) is dissolved in 189.16 g H2O? The freezing point depression constant is 1.8600 (°C*kg)/mol. Assume any salt is completely ionic!

@X@user.full_name@X@ @GMU: Initially there were equilibrium concentrations of 0.1755 M A, 0.2500 M B, and 0.1755 M C. Which change will cause the equilibrium to shift from left to right? Use the reaction below.4A → 4 B +3 C Kc = 0.663

@X@user.full_name@X@ @GMU: Initially there were equilibrium concentrations of 0.3076 M A, 0.2369 M B, and 0.1811 M C. Which change will cause the equilibrium to shift from left to right if the reaction is exothermic? Use the reaction below.5A(aq) → 2B(aq) +4C(aq) K = 1.376

@X@user.full_name@X@ @GMU: What is the activation energy (in kJ/mol) for the reaction below if the rate constants are 2.700e-4 M-1s-1 at 327.00°C and 7.67e-4 M-1s-1 at 346.45°C?H2(g) + I2(g) → 2HI(g)