Question

Calculate the approximate number of molecules in a drop of water with a mass of 0.10 g.

Answer 1

Answer:

The correct answer is B) 3 x 1021 molecules

Explanation:

We use Avogadro's number (in one mole of compound there are 6, 02x10e23 molecules) and calculate the weight of one mole of water:

Weight 1 mol H20 = (Weight H)x2 + Weight 0= 1 g/mol x 2 + 16 g/mol=

Weight 1 mol H20 = 18g/mol

18g---------6,02x10e23 molecules

0,10g-------x=(0,10gx6,02x10e23 molecules)/18g=3,34x10e21 molecules