Answer: 6,25 moles
Explanation: mark amount of butane x.
From equation you can calculate x in a following way:
2/x = 8/25. 8x = 50. And x = 6,25
Answer: (3) ppm
Explanation: Concentration is defined as the amount of solute dissolved in a known amount of the solvent or a solution.
Parts per million (ppm) is used to express the concentration when a very small quantity of solute is present in a large quantity of the solution. It is defined as the mass of solute present in one milion
parts by mass of the solution.

L/s is used to express flow rate.
J/g is used to express energy per unit mass.
kPa is used to express pressure.
Protons .because electron has negative charge and proton has positive charge.
What are your answer choices? Scientists express the weight in AMU’s so that they can easily think about the weight of the atom. If it is expressed in grams, they’re constantly dealing with a weight that’s around 10^-24 grams, which is hard to deal with.