One mole is equal to how many particles

What is the enthalpy of combustion (per mole) of c4h10 (g)? –2,657.5 kj/mol –5315.0 kj/mol –509.7 kj/mol –254.8 kj/mol

50 points! need answer asap. what type of organic compound contains the following functional group? (2 points)

Scuba divers use tanks of compressed air to them breathe. gases can be compressed because?