Blog

@X@user.full_name@X@ @GMU: Radioactive substances decay by first-order kinetics. How many years would be required for a sample containing carbon-14 to decrease to 53.91% of its initial activity? The half-life of carbon-14 is 5.73e3 years.

@X@user.full_name@X@ @GMU: The osmotic pressure of a 11.798 mM solution of Ba(NO3)2 is 0.610 atm at 18.52 °C. How many ions per formula unit of Ba(NO3)2 must there be? The compound may not be completely ionic.

Determine if the forward reaction for the energy level diagram is endothermic or exothermic and what the ΔH for the reverse reaction is.

@X@user.full_name@X@ @GMU: A mixture containing an initial concentration of 0.1987 M for H2 and 0.1540 M for Cl2 is allowed to come to equilibrium (see reaction below). What must be the equilibrium concentration of HCl?H2(g) + Cl2(g) → 2HCl(g) Kc = 5.00e16

@X@user.full_name@X@ @GMU: Determine the mole fraction of cyclohexene if 6.8460 g of cyclohexene, C6H10, was mixed with 8.49 g of cyclopentene, C5H8. MW(C6H10) = 82.145 g/mol; MW(C5H8) = 68.119 g/mol.

@X@user.full_name@X@ @GMU: The reaction below is a exothermic reaction. What would one have to do to increase the size of the equilibrium constant?2PCl3(g) + O2(g)→2POCl3(g)

John Schreifels @GMU: When 8.824 g of glucose was dissolved in 103.7 g of benzene, the freezing point was 276.2 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 formation of I2 if the initial concentration of IO3− was 0.3797 M and decreased to 0.3284 M after 0.2138 hours. Use the reaction below.IO3− + 5I− + 6H+ → 3I2 + 3H2O

@X@user.full_name@X@ @GMU: How many grams of sodium hydroxide, NaOH, would be required to prepare a 0.1536 m NaOH solution by combining this compound with 0.3007 L of water (assume a density of 1.00 g/mL)? The molecular weight is 39.9971 g/mol.

@X@user.full_name@X@ @GMU: A possible reaction mechanism for the reaction between nitric oxide and bromine is shown below. Which species listed below is an intermediate? (1) NO(g) + Br2(g) → NOBr2(g) Slow, rate determining (2) NO(g) + NOBr2(g) → 2NOBr(g) Fast, equilibrium