Physics homework - please help!

i would really appreciate it if you only solve even one question. i was absent on the day teacher tought this topic.
How much negative electric charge is contained in 10 moles of carbon?

A container holds a gas consisting of 1.20 moles of oxygen molecules. One in a million of these molecules has lost a single electron.What is the net charge of the gas?

A system of 1460 particles, each of which is either an electron or a proton, has a net charge of −7.104×10−17 C. How many electrons are in this system? What is the mass of this system?

Find the net charge of a system consisting of 5.7×107 electrons.

Find the total electric charge of 1.3 kg of electrons.

Find the total electric charge of 1.3 kg of protons.


Find the net charge of a system consisting of 6.09×10^6 electrons and 7.63×10^6 protons.

Find the net charge of a system consisting of 221 electrons and 150 protons.

That's a lot of questions so I'll just tell you what you need to know for them.
1 mol is 6.02x10^23 molecules (or atoms)
1 electron has a charge of -1.6x10^-19 C (Coulombs)
1 proton has a charge of +1.6x10^-19 C (Coulombs)
1 electron has a mass of 9.11x10^-31 kg
1 proton has a mass of 1.673x10^-27 kg

To find the net charge of a system you would just add the charges of the electrons and protons

Ex. (the last question)
(221)*(-1.6x10^-19 C) + (150)*(+1.6x10^-19 C) = -1.136x10^-17 C

The 3rd question seems to be the hardest so I'll do that one, too.
Since the charge of the system is negative, you know there are more electrons than protons. To find out exactly how many more there are you would just divine the charge of an electron from the net charge of the system.
-7.104x10^-17 C / -1.6x10^-19 = 444 more electrons than protons
Subtract 444 from the total number of particles and divide that by 2 to find the number of protons
(1460 - 444) / 2 = 508 protons