Nalorphene `(C_19H_21NO_3)`, similar to morphine, is used to combat withdrawl symptoms in narcotic users. Dose of nalrophene generally given is 1.5 mg. Calculate the mass of `1.5xx10^-3m` aqueous solution required for the above dose.

Suppose a pure Si crystal has 5xx16^28 atoms. m^(-3) . It is doped by 1ppm concentraction of pentabalent As. Calculate the number of electron and holes. Given that n_i=1.5xx10^16m^(-3) .

For the reaction 2A harr 4B + C the concentration of B is increased by 5xx10^-3 mol L^-1 in 10 seconds. Calculate the rate of appearance of B.

For the reaction 2A harr 4B + C the concentration of B is increased by 5xx10^-3 mol L^-1 in 10 seconds. Calculate the rate of disappearance of A.

Calculate the force of gravitation between the earth and the Sun, given that the mass of the earth = 6 xx 10^24 kg and mass of the Sun = 2 xx 10^30kg . The average distance between the two is 1.5 xx 10^11 m .

Calculate the amount of work done for a wire which area of cross section 10^-6m^2 and length 1.5m to increase the length 4 xx 10^-3 m. Young's modules of elasticity 2 xx 10^(11N//m^2) .

For a reaction 2A rarr 4B+C , the concentration of B is increased by 5.0xx10^(-3) molL^(-1) in 10 seconds. Calculate the rate of disappearance of A.

The work function of a metallic surface is 2.5 eV. Ultraviolet light of wavelength 2000Å is allowed to be incident on the metallic surface. Calculate Stopping potential. (Given Planck's constant h = 6.63 xx 10^(-34) J-s , electronic charge e = 1.6 xx 10^(-19) C, electron mass m = 9.1 xx 10^( -31) kg

For the reaction 4NH_3 + 5O_2 rarr 4NO + 6H_2O , the rate of formation of NO is 3.6xx10^-3 mol L^-1s^-1 . Calculate the rate of disappearance of NH_3 and the rate of formation of H_2O .