The number of molecules in 1.00 liter of O2 gas at 56◦C and 821 torr is
1. 1.83 × 1025 molec.
2. 32 molec.
3. 2.24 × 1023 molec.
4. 2.41 × 1022 molec.
5. 4 × 10−2 molec.