Answer:
(Rounded to SigFigs)
A. 8.14 * 10^23 Molecules CS2
B. 1.53 * 10^23 Molecules As2O3
C. 7.53 * 10^23 Molecules H2O
D. 9.0 * 10^25 Molecules HCl
Step-by-step explanation:
To determine the number of molecules in a given amount of substance (in moles), you can use Avogadro's number, which is approximately 6.022 × 10^23 molecules/mol.
a. 1.35 mol carbon disulfide:
Number of molecules = 1.35 mol × (6.022 × 10^23 molecules/mol) = 8.1437 × 10^23 molecules
b. 0.254 mol As2O3:
Number of molecules = 0.254 mol × (6.022 × 10^23 molecules/mol) = 1.530988 × 10^23 molecules
c. 1.25 mol water:
Number of molecules = 1.25 mol × (6.022 × 10^23 molecules/mol) = 7.5275 × 10^23 molecules
d. 150.0 mol HCl:
Number of molecules = 150.0 mol × (6.022 × 10^23 molecules/mol) = 9.033 × 10^25 molecules
In the image attached, you can see how Mols cancels out and you're left in molecules instead using the train track method.
Hope this helps!