An alpha particle (mass=6.6x10^-24g) emmited by a radium isotope travels at 3.4x10^7 mi/hr. what is its de broglie wavelength in meters

Amixture initially contains a, b, and c in the following concentrations: [a] = 0.300 m , [b] = 1.05 m , and [c] = 0.550 m . the following reaction occurs and equilibrium is established: a+2b⇌c at equilibrium, [a] = 0.140 m and [c] = 0.710 m . calculate the value of the equilibrium constant, kc.