A mole of nitrogen gas N2 and a mole of carbon dioxide gas CO2 contain the same number of molecules.

This statement is indeed correct. A mole is a unit used in chemistry to denote a specific amount of substance. Specifically, one mole of any substance contains approximately $6.022 \times 10^{23}$ molecules, known as Avogadro's number.

Understanding Moles

1. Definition of a Mole: A mole of any substance contains exactly $6.022 \times 10^{23}$ entities (which could be atoms, molecules, ions, etc.).
2. Application to Gases: It is important to note that irrespective of the type of gas, a mole of gas at standard temperature and pressure (STP) occupies a volume of 22.4 liters and contains the same number of molecules as any other mole of gas.

Example

• A mole of nitrogen gas $N_2$ contains $6.022 \times 10^{23}$ nitrogen molecules.
• Similarly, a mole of carbon dioxide gas $CO_2$ also contains $6.022 \times 10^{23}$ carbon dioxide molecules.

Conclusion

Therefore, when you have a mole of $N_2$ and a mole of $CO_2$, both contain the same number of molecules, which is $6.022 \times 10^{23}$. This fundamental principle of moles is crucial for understanding stoichiometry and various chemical reactions.