Answer: 3 x 10^24 molecules CH4
Step-by-step explanation: Avogadro's number represents the number of particles in one mole of a substance. It is approximately 6.02 x 10^23 particles per mole.
To convert 5 mol CH4 to molecules,
we can use the following calculation:
5 mol CH4 x 6.02 x 10^23 molecules/mol ≈ 3.0 x 10^24 molecules CH4
Rounding to one significant figure, the answer is 3 x 10^24 molecules CH4.