Aconducting sphere has a net charge of –6.4 × 10–17
c. what is the approximate number of excess electrons on the sphere?

The charge of a single electron is -1.6 x 10^(-19) C. To figure out the total number of excess electrons, divide the net charge by the charge of a single electron:

-6.4 x 10^(-17) / -1.6 x 10^(-19) = 400

There are about 400 excess electrons on the sphere.

Hbr dissociates to form h+ and br-ca(oh)2 dissociates to form ca2+ and 2oh-the h+ and oh- react to form waterassuming the reactants are dissolved in water, the net reaction is h+ + oh- —> h2oif you’re asked to show all components of the reaction, the complete reaction is 2hbr + ca(oh)2 —> cabr2 + 2h2o

Rate law for this reaction israte of the reaction = k[a]²[b].second order in a  means concentration of a in power of two, and  first order in b means concentration of b in power of one.