What is the total charge of all the electrons in 1.0 kg of h20?

Answer 1

To answer this, first calculate how many electrons are in 1 kg of water, then multiply that by the charge per electron (1.602 x 10^-19 coulombs).

The molecular weight of water is 18, so there are 1000 / 18 = 55.55 moles of water in 1 kg. Multiply that by Avogadro's number (6.02 x 10^23) to get the number of water molecules

55.55 x 6.02 x 10^23 = 3.34 x 10^26.

Each water molecule has 10 electrons, so multiply that answer by 10 to get the total number of electrons,

3.34 x 10^27 electrons per kg water.

Finally, multiply the number of electrons by the energy per electron (1.602 x 10^-19 coulombs).

3.34 x 10^27 electrons x 1.602 x 10^-19 coulombs/electron = 5.29 x 10^8 coulombs.

Answer 2

1.0 kg H2O x (1000g H2O/1 kg H2O) x (1 mol H2O/18.02 g H2O) x (6.022 x 10^23 molecules H2O/1 mol H2O) x (10 electrons/ molecule H2O) = the answer

Solve the above. This is dimensional analysis.

Each H has one electron and each O has 8 electrons.

Answer 3

This is a fun question, that is going to require some clever use of several skills.

First we need to be familiar with the unit of charge that we will be using for conversion. Electric charge is measured in Coulombs, and one mole of electrons has a charge of 96,485 C. This amount of charge is called a Farady. Remember when doing stoichiometry, always try to connect things through moles.

We also need to know the number of electrons in a molecule of water. The total from two hydrogens and an oxygen should be: 1 + 1 + 6 = 8 electrons.

Here is the series of calculations:

1000g H₂O * (1 mol H₂O/18.02 g) = 55.5 mol H₂O

55.5 mol H₂O * (8 mol e^-/1 mol H₂O) = 444 mol e^-

444 mol e^- * (1 Farday/mol e^-) = 444 F

If we need the answer in Coulombs instead, then we need a different 3rd calculation

444 mol e^- * (96,485 C/mol e^-) = 4.28 * 10⁷ C

The charge should be reported as a negative number because electrons are assigned a negative charge.