Total charge of electrons

What is the total charge of all the electrons in 2.37 kg of H2O?

Two conducting wires each of length L are...

Two conducting wires each of length L are connected to a knob, whereby a total electric charge Q is deposited onto two small spherical metallic spheres, each of mass m and diameter d, at the end of the wires. We observe each wire of this electroscope to lie at an angle q from the vertical. Find an expression for the charge Q in terms of the given quantities L,m,d and q as well as physical constants. You have now calibrated the electroscope, and may use it for quantitative experiments. q L Compute the electric field, in both components and as magnitude and direction, at the midpoint between the two hanging masses

capacitance and electric potential

A 2.61 micro F capacitor is charged to 1380 V and a 7.79 micro F is charged to 490 V. These capacitors are then disconnected from their batteries, and the positive plates are now connected to each other and the negative plates are connected to each other. What will be the potential difference across each? What will be the charge on the 2.61 micro F capacitor and what will be the charge on the 7.79 micro F capacitor?

capacitor

A 0.188F capacitor is desired. What area must the plates have if they are to be separated by a 1.67mm air gap?

Capacitor

Im going to paste the problem here but for the image can you guys please follow the link below. A capacitor of capacitance C1 is given charge Q0, as shown. It is then connected as shown to another uncharged capacitor of capacitance C2. With clearly displayed reasoning, find the voltage across each capacitor and the charge on each side of each capacitor, including the signs. What is the voltage at the upper right corner with respect to a point at the upper left corner? http://www.colorado.edu/physics/phys2020/phys2020_sp04/index.html