how many numbers of oxygen molecules are present in 3 litres of CO2 at STP?
zero. Only CO2 exists in the contaner, no O2 nor any other gas.
To find the number of oxygen molecules in 3 liters of CO2 at STP (Standard Temperature and Pressure), we need to use the ideal gas law and the molar ratio of the elements in CO2.
The ideal gas law states: PV = nRT, where P is the pressure, V is the volume, n is the number of moles, R is the ideal gas constant, and T is the temperature.
At STP, the pressure is 1 atmosphere, the temperature is 273.15 Kelvin, and the gas constant R is 0.0821 L·atm/(K·mol).
We can rearrange the ideal gas law to solve for the number of moles:
n = PV / RT
Now, let's calculate the number of moles of CO2 in 3 liters at STP:
V = 3 L
P = 1 atm
T = 273.15 K
n(CO2) = (1 atm * 3 L) / (0.0821 L·atm/(K·mol) * 273.15 K)
= 0.1367 mol
From the balanced chemical equation for CO2, we know that there is one mole of carbon (C) and two moles of oxygen (O2) in one mole of CO2.
So, the number of moles of oxygen (O2) in 0.1367 moles of CO2 would be:
n(O2) = 2 * n(CO2)
= 2 * 0.1367 mol
= 0.2734 mol
Finally, to convert the moles of oxygen to the number of oxygen molecules, we use Avogadro's number, which is approximately 6.022 x 10^23 molecules/mol.
Number of oxygen molecules = n(O2) * Avogadro's number
= 0.2734 mol * 6.022 x 10^23 molecules/mol
= 1.647 x 10^23 molecules
Therefore, there are approximately 1.647 x 10^23 oxygen molecules in 3 liters of CO2 at STP.