Define modulation index. Why is it kept low? What is the role of a band pass filter ?

Colloidal solution of gold is prepared by striking an electric are between gold electrodes kept in water. What is this method called as? Why is it regarded as a dispersion method?

H_(2)(g)+I_(2)harr2HI+Heat answer the following questions related to the given system at equlibrium. a) The rate of which reactions increases when the concentration of I_(2) is increased? b) What is the influence of pressure on this system? c) HI must be kept at low temperature to prevent its decomposition. Give reason.