Question

A gas cylinder contains exactly 15 moles of oxygen gas (O2). How many molecules of oxygen are in the cylinder? 4.01 × 1022 molecules 6.02 × 1023 molecules 9.03 × 1024 molecules 2.89 × 1026 molecules

Answer 1

The answer is 9.03 × 10²⁴ molecules.

Avogadro's number is the number of units (atoms, molecules) in 1 mole of substance.
Make the proportion.
6.02 × 10²³ molecules per 1 mol
x per 15 mol

6.02 × 10²³ molecules : 1 mol = x : 15 mol
x = 6.02 × 10²³ molecules * 15 mol * 1 mol
x = 90.3 × 10²³ molecules
x = 9.03 × 10 × 10²³ molecules
x = 9.03 × 10²³⁺¹ molecules
x = 9.03 × 10²⁴ molecules

Answer 2

Answer: C

Explanation: just got it correct