Answer:
A. 2.107x10^24
Explanation:
1 mole is defined as the particles containing in 12g of 12-C. That is 6.022x10²³ particles.
When you say 1 mole of atoms means 6.022x10²³ atoms, 1 mole of molecules means 6.022x10²³ molecules, etc.
Now, 3.5 moles of H₂O are:
3.5mol * (6.022x10²³ molecules / 1mol) = 2.107x10²⁴ molecules of H₂O.
Thus, right answer is:
A. 2.107x10^24
