How many electrons are found in a sample of dioxygen gas contained in a "0.448 L" container at STP?

3 Answers
Aug 19, 2017

1.20 x 10^22 electrons

Explanation:

The no of electrons present in448 ml of O2 at STP
At STP conditions 1 mole of O2 gas = 6.023 x 10^23 electrons

1 mole = 22.4 L
So, 22.4 L of O_2 = (6.023 x 10^23 electrons)
0.448 L of O_2 = (6.023 x 10^23 electrons)x (0.448)]/22.4L
= 1.20 x 10^22 electrons

Aug 19, 2017

See.

Explanation:

22400ml O_2 contains 16×N_A electrons
1ml O_2 contains (16×N_A)/22400electrons
Hence,448ml contains (16×N_A×448)/22400 electrons=0.32×N_A
Here, N_A is Avogadro number.

Aug 19, 2017

About 1.93 xx 10^23 electrons.


Assuming your definition of STP is 0^@ "C" and "1 atm", the molar volume of "O"_2, assuming it is an ideal gas, is based on the ideal gas law:

PV = nRT

for pressure P, volume V, mols n, temperature T, and universal gas constant R.

Rearranging, we get...

V/n = (RT)/P

= (("0.082057 L"cdot"atm/mol"cdot"K")("273.15 K"))/"1 atm"

= "22.414 L/mol"

So, with this molar volume, we compare ratios:

"0.448 L"/("x mols") = "22.414 L"/"mol"

=> n_("O"_2) = "0.0200 mols"

Each "O" atom contains 8 electrons, so each "O"_2 molecule contains... well, 16.

"0.0200 mols O"_2 harr "0.320 mols e"^(-)

And thus, the number of electrons is given by

color(blue)("Number of electrons") = "0.320 mols e"^(-) xx 6.0221413 xx 10^(23) "mol"^(-1)

= ulcolor(blue)(1.93 xx 10^(23)color(white)(.)"e"^(-))