Question

What is the total negative charge, in coulombs, of all the electrons in a small 0.900 g sphere of carbon? one mole of c is 12.0 g , and each atom contains 6 protons and 6 electrons?

Answer 1

To calculate the total negative charge in a 0.900 g sphere of carbon, the number of electrons is determined from the mass and multiplied by the charge per electron, yielding -1.1565 ×
`10^3`Coulombs.

Step-by-step explanation:

The question is asking to calculate the total negative charge of electrons in a given mass of carbon. Knowing that one mole of carbon weighs 12.0 g and contains Avogadro's number of atoms, we can first determine the number of moles of carbon in the 0.900 g sphere. The number of moles is 0.900 g / 12.0 g/mol, which equals 0.075 moles. Each carbon atom has 6 electrons, so we multiply the number of moles by Avogadro's number (6.022 ×
`10^(23)` atoms/mol) to find the total number of electrons in the sphere. After finding out the total number of electrons, we multiply this by the charge of a single electron, which is -1.6 ×
`10^(-19)` C. Therefore, the total negative charge can be calculated as follows:

0.075 moles × 6.022 ×
`10^(23)` electrons/mol × -1.6 ×
`10^(-19)` C/electron = -7.228 ×
`10^(18)` electrons × -1.6 ×
`10^(-19)` C/electron = -1.1565 ×
`10^3` C

Thus, the total negative charge is -1.1565 ×
`10^3` Coulombs.

Answer 2

The first thing you have to do is find the number of mols. That's done in terms of the masses.
mol = mass of sample / molar mass
mol = 0.900 / 12.0
mol = 0.0750 mol Carbon

Next Each mol of carbon contains 6 mol of electrons.
mol electrons = 6 * mol of carbon
mol electrons = 6* 0.0750 = 0.450 mol

Next find out how many electrons are in 0.450 mol
1 mol = 6.02 * 10^23
0.450 mol = 6.02 * 10^23 * 0.45 = 2.71 * 10^23 electrons

Finally find the charge in coulombs
1 electron has a charge of 1.60 * 10 ^- 19
2.71 * 10^23 electrons have a charge of 1.6*10^-19 * 2.71*10^23
The answer is 43360 Coulombs = 4.34 * 10^4 coulombs.

I have deliberately not used textbook formulas because each textbook has its own format.