Question

How many atoms of silicon are in 0.75 mol of disilicon hexahydride, Si2H6? A.4.5x 1023 atoms B.6.02 x 1023 atoms C.8.0 x 1023 atoms D.9.0x1023 atoms

Answer 1

D. 9.0x10²³ atoms

Step-by-step explanation:

First we use Avogadro's number to calculate how many molecules of Si₂H₆ are there in 0.75 mol:

• 0.75 mol * 6.023x10²³ molecules/mol = 4.52x10²³ molecules

There are 2 Si atoms in one Si₂H₆ molecule, that means that in 4.52x10²³ Si₂H₆ molecules there will be:

• 2 * 4.52x10²³ = 9.03x10²³ Si atoms

Thus the answer is option D.